Evidence using s20 powers

Consequences of obtaining evidence improperly

If you obtain evidence improperly, for example by exceeding any of the powers set out in s20, then a court may rule that the evidence would have such an adverse effect on the fairness of the proceedings that it should not be admitted in evidence. Any unjustified use of your powers under s20 HSWA 1974 could also provoke a civil action for damages 1. If the impropriety is sufficiently serious it may form the basis of an abuse of process argument.

For example s20 does not give you the power to search premises for documents or articles. If it is necessary to search premises you should consult the Procurator Fiscal.


You have the power to require any person to produce any books or documents required to be kept under any of the relevant statutory provisions, and any other books or documents which are necessary for you to see for the purposes of your investigation. 2 This would include any document which assists you in deciding whether you should prosecute.

You have the power to inspect and take copies of such documents. If you do not take a copy, you should carefully note the contents in your notebook. Section 20(2)(k) does not give you the right to seize original documents. If you need to do this, you should refer to the previous section on 'Original documents or copies'?

Where you do not have access to copying facilities on site, you may need to remove the original for copying. In such cases, you should give a responsible person a notice identifying the document and stating that you have taken possession of it under your s20 powers 3 but will return it as soon as the necessary copy has been made. You should record in your notebook as to why you took the original for copying and also note when you returned the original.

Reference to new physical evidence obtained

You may have to go back and ask a witness about documents or objects that you have subsequently obtained. If you have already taken a statement from the witness you may have to take a further statement to reflect their response to documents subsequently obtained. For example, where a document has been produced to show the steps taken with regard to safety, you should ask relevant witnesses about the document, in order to discover whether they knew of the document, and whether such steps were in fact taken.

You should also ask your expert to comment on the reasonably practicable steps required and the adequacy of the steps taken.

Obtaining information in writing

Section 20(2)(j) allows inspectors to seek and obtain information. In normal circumstances you will seek to obtain the information face to face by collection f a witness statement. However, if this is not possible or appropriate the section does allow you to seek and obtain the information in writing. 4

Documents from computers

Generally it is not the computer itself which is evidence in a case, but the information held within the computer. In straightforward cases, if you require information which you know is held on the computer, you should ask the duty holder to print out the information for you, using section 20(2)(m) powers.

You should ask the duty holder if the computer is working properly as far as s/he knows. In less straightforward cases (for example, where you needed to prove that an entry was falsely dated, or in cases where the duty holder is not cooperative) you may need to take a computer expert with you, using section 20(2)(c) powers, who can examine it and take any necessary copies using section 20(2)(m) powers.

In exceptional cases where a large amount of relevant material is known to be held on computer, a computer expert can 'image' the computer's hard drive: the expert then takes the image away to obtain the necessary material, relying on section 20(2)(m). This reduces the impact on the duty holder as the computer is unavailable for the minimum length of time. However, such an action would have to be proportionate and necessary in all the circumstances of the case for a court to regard such action as justified.

Requests for specialist help should be done through the normal channels in the Directorates/Divisions.

Power to leave undisturbed

You have power to direct that the premises, or any part of them, or anything in them, be left undisturbed for so long as is reasonably necessary for the purpose of your investigation 5. This power may be exercised, for example, where:

  • the configuration of the site or machine at the time may be essential for determining physical evidence;
  • where you decide that investigation by your expert is necessary;
  • where you need to return with specialist measuring or testing equipment.

You may be able to arrange informally with an employer that the item or area is left undisturbed, but where you are not certain that an employer will comply, you should issue a formal notice. A formal notice to leave undisturbed should be in writing and include:

  • reference to s20(2)(e);
  • a fixed time during which no disturbance should be made. This can later be extended if necessary.

You should not rely on the fact that an employer is going to obtain a report on equipment, because that report may be the subject of legal professional privilege which will mean that it will not be disclosed to you. "Legal professional privilege" is considered in more detail later in this section.

Taking possession of an article/substance

You have power to take possession of any article or substance which appears to you to have caused or to be likely to cause danger to health or safety, in order to examine it, ensure that it is not tampered with, or to ensure that it is available for evidence in a prosecution 6.

When you do so, you must leave a notice with a responsible person at the premises or, where this is impracticable, fix in a conspicuous position:

  • giving sufficient details of the article to identify it; and
  • stating that you have taken possession of it under your s20 (2)(i) power 7.

Unless it is not practicable, before taking possession of an article/substance under your s.20 (2)(i) power, you should leave a marked sample of the substance/article, with a responsible person on the premises 8. Use Form LP6 as a Notice of Taking Possession.


You have power to take samples of any articles or substances and to take atmospheric samples 9. The occupier or other responsible person must always be informed of the intention to take samples for analysis.

When the sample has been collected it should be divided into three parts. One part should be given to the occupier, another sent for analysis and the third retained by the inspector.

Each item must be uniquely identified by a label and recorded, using the proper containers, packing, labels and seals. The labels should state the premises of origin, a description of the sample, a number if there is more than one sample, the date, and your name and title.

Samples are dealt with in more detail in "Expert Evidence".

Analysis and tests

You can dismantle, or subject to any process or test, an article or substance which appears to you to have caused or to be likely to cause danger to health or safety 10.

Where any person responsible for the premises from which the article was taken requests to be present when any dismantling or testing is carried out this should be allowed 11. You should also contact them if the test will irreversibly alter the article to give them an opportunity to be present.

So far as possible, you should retain enough of the item to facilitate further independent tests. If this is not possible, you should video, photograph or otherwise record the test to ensure that the results can be proved in court.

You have power to take such measurements and photographs and to make such recordings as you consider necessary to your investigations 12.

Recording actions

All the circumstances surrounding the taking of a sample or the taking possession of an article for tests should be noted carefully in your notebook and included in your statement.

Your powers under section 20 cannot compel the production of documents which are entitled to be withheld on grounds of legal professional privilege 13.

The expression 'legal professional privilege' is not widely used in Scotland: a more appropriate term is 'confidentiality of communications'. The test under section 20 is whether the Court of Session would refuse to make an order for the production of documents on the grounds of legal professional privilege. In interpreting section 20 the Scottish courts will apply the Scottish common law on confidentiality, not the English approach to legal professional privilege. Although the law is similar in both jurisdictions, there nevertheless are differences of approach.

In Scotland confidentiality covers two concepts: solicitor and client privilege on the one hand and, on the other the privilege attaching to communications made post litem motam (in contemplation of litigation). Any document that is privileged, either through solicitor and client privilege, or post litem motam will be confidential. Courts respect the principle of confidentiality and will not order disclosure of documents or communications that are confidential; either through solicitor client privilege, or privilege post litem motam. There are very limited exceptions to this rule, for example, where the communication or document relates to fraud or other illegal act and the legal advisor is directly involved in the illegal activity, then the court will order disclosure notwithstanding the fact the document is confidential.

The privilege is that of the client, so that the client is entitled to waive privilege and disclose the document. Once privilege has been waived and a document disclosed, then it can be used in evidence.

The class of documents or communications that are confidential post litem motam, includes, not only correspondence between a solicitor and client, but also all documents generated after it is apparent that there is likely to be judicial proceedings. The rationale for this rule is that every party should be entitled to pursue investigations into the causes of accidents/incidents free from the risk of disclosure. In Scotland, formal court proceedings do not have to have commenced before the privilege will apply, and, even once a case has been concluded relevant documents and communications remain confidential.

Most post accident reports compiled by employers will be confidential on the basis they are privileged post litem motam. However, there is one type of post accident report that is not treated as confidential, and is an exception to the general rule. A post accident report made by an employee who was present at the scene of an accident, if made at or about the time of the accident, will not attract the privileged and is not confidential. The rationale for this exception is said to result from the fact such reports are made as part of an employer's routine duty, and generally likely to represent an unvarnished account of what happened. Although this reasoning has been subject to criticism, the exception nevertheless stands.

You should not rely on the fact that an employer is going to obtain a report on equipment, because that report may be the subject of privilege, which will mean that it will not be disclosed to you. You should not therefore routinely request investigation reports where prosecution is possible.


  1. Section 26 empowers HSE to indemnify inspectors. Back to reference of footnote 1
  2. HSWA 1974, s.20 (2)(k). Failure to produce a document could give rise to a separate offence under s.33 (1)(e). Back to reference of footnote 2
  3. Could be a justified use of s. 20(2)(m) and possibly by analogy with exercise of the powers under s.20 (2)(i). Back to reference of footnote 3
  4. London Borough of Wandsworth -v- South Western Magistrates Court [2003] EWHC 1158 Admin. Back to reference of footnote 4
  5. HSWA 1974, s.20 (2)(e). Back to reference of footnote 5
  6. HSWA 1974, s.20 (2)(i). Back to reference of footnote 6
  7. Form LP6. Back to reference of footnote 7
  8. HSWA 1974, s.20 (6). Back to reference of footnote 8
  9. HSWA 1974, s.20 (2)(g). Back to reference of footnote 9
  10. HSWA 1974, s.20 (2)(h). Before exercising this power, you must consult any person you consider appropriate to find out what dangers there may be in dismantling or testing. You should therefore consult your expert, and in some cases, management or technicians at the premises: s.20 (5). Back to reference of footnote 10
  11. HSWA 1974, s.20 (4). Although this right does not extend to Trade Unions, it is good practice not to exclude them if they wish to be present. A person who has a right to be present does not have a right to be represented at the test, but such requests should normally be granted. Back to reference of footnote 11
  12. HSWA 1974, s.20 (2)(f). Back to reference of footnote 12
  13. HSWA 1974, s.20 (8). Back to reference of footnote 13

Is this page useful?

Updated 2023-11-13