Management of access to material by interested parties at HSL to meet HSE investigation requirements


This guidance advises on the requirements for access by interested parties to HSE's evidential material held at HSL.


This guidance applies where evidential material, gathered during the course of an investigation, is held at HSL, eg for analysis or testing. It sets out the measures that must be taken to ensure that persons who have a legitimate legal interest in the material – "interested parties" – are able to have access to it where so entitled, while protecting investigations and potential legal proceedings from being compromised. In this context, interested parties include:

  • any potential defendants, or in Scotland the potential accused
  • their legal representatives and technical advisers
  • persons who have responsibility for premises
  • Coroner's officers, Procurator Fiscal, police, other regulators and medical examiners
  • any person ordered by a court.

The entitlement of any interested party to access the material will depend upon the status of the material in relation to the investigation. In civil matters HSE, or in Scotland the Procurator Fiscal, may permit limited access or disclosure, only after legal proceedings have been completed.


Action by lead investigator and specialist

The lead investigator retains overall responsibility for all evidential material and therefore has the central role in managing access to any items at HSL. HSE's policy, agreed with HSL, is for all requests for such access to be directed to the lead investigator.

If destructive or dismantling tests are to be undertaken, the lead investigator should proactively inform interested parties and offer access to witness these tests. Similarly, if an expert witness will be required at a later date, they may need to be involved when tests are undertaken.

Lead investigators should consider the following issues in relation to requests and take appropriate action as indicated below:

  • receipt and routing of requests from interested parties
  • establishing their entitlement to access
  • defining the scope of access to be allowed
  • supervision and liaison arrangements for the visit.

Receipt and routing of requests

  • ensure that all relevant staff are aware that any requests they receive should be directed to the lead inspector
  • accept requests only when they are made in writing, and advise interested parties to that effect where requests are made by other means.

Entitlement to access

  • confirm that the request adequately describes the reason for wanting to see the material, whether they intend to bring someone else with them, and if so, who, and what they would like to do to or with the material
  • decide whether to grant the request in principle, guided by the criteria in "Background".

Scope of access

  • agree the scope of access with the interested party, first consulting with the specialist where appropriate
  • seek the permission of the Procurator Fiscal for all requests in Scotland
  • confirm permission and scope of access in writing, copied to the relevant specialist and to HSL (see Appendix 2 for outline text of letter)
  • agree with HSL where the work is to be recorded, ie against a previous project (if it is still open, and appropriate) or against a new project
  • include consideration of the following when confirming the scope of access to HSL and interested parties:
    • numbers and identity of those who have been given permission to attend (Note: if they have not been identified to HSL, then they will be not be permitted access to the site)
    • specifying the material to which access has been granted (including the HSL job reference number)
    • the level of access permitted – eg observation
    • arrangements for and confirmation of the date and time for the visit
    • health and safety precautions, eg PPE
    • additional facilities HSL can provide to assist the level of access agreed
    • who from HSE should also be present
    • HSL requirements for visitors
    • HSL contact
    • constraints on the use of recording media – eg video of other evidence in the store.

Supervision and liaison arrangements

  • plan for you or the specialist to be present during the visit to supervise the interested parties, unless there is no need for an HSE presence, for example, visits limited to visual examination of the material that HSL can supervise
  • determine with HSL which member of their staff will be appointed to act as host for the visit (see "Action by HSL staff"), and confirm who will do what to fulfil the necessary supervisory functions.

Action by HSL

HSL are responsible for appointing an HSL officer to act as host for the attendance of interested parties for the purpose of organizing the detail of the visit and providing liaison between HSE and the interested parties.

The HSL host should:

  • record the name, and party they are representing - of each interested party
  • ensure the viewing of evidence (for continuity of evidence purposes) is overseen by HSE or HSL
  • agree respective responsibilities with any HSE staff present
  • restrict access by interested parties to the materials specified in the scope
  • record and update any evidence bags that are opened, annotating the evidence tags/ bags in accordance with Operational Guidance: Material and evidence management (collection, retention and disposal).
  • record which items are reviewed and what has been done to them eg measurements, photographs, etc.
  • prevent discussion about the investigation between HSL staff and interested parties
  • prepare a statement detailing the factual elements of the above when necessary and so instructed.


Persons facing criminal prosecution have a right to examine the material involved. Similarly, where material taken into possession is going to be dismantled or subjected to any process or test, the owner (or person responsible for the premises) is entitled to witness such activities. Interested parties for civil matters may also request access.

Interested parties are entitled to be accompanied by technical representative(s) to assist in their understanding of any processes or tests. If destructive or dismantling tests are to be undertaken, the lead investigator should inform interested parties and offer access to witness these test. If the specialist determines that testing is required then they need to inform the lead investigator so that they may inform the owner and other relevant interested parties. It is good practice (in appropriate circumstances) to discuss the scope of the tests with interested parties and consider any suggestions they may offer.

If testing is being undertaken by HSL the need for fairness and continuity of evidence needs to be balanced with the need to ensure the presence of observers will not impede or inhibit the test. For this reason the numbers attending may need to be limited.

HSL staff are not permitted to engage with interested parties in conversation about ongoing criminal investigations. Any such questions should be directed to the HSE lead investigator. Interested parties should only be given access to what has been agreed with HSE, and requests to see other materials should be declined.

Video recording of tests may be undertaken by HSE to create a historical record. The lead investigator may disclose such recordings to interested parties when considered appropriate.

The confirmatory letter to interested parties informs them that HSL are unable to provide facilities for formal meetings.


No specific organisational requirements.

Further references

For information relating to experts and evidence please see the operational guidance detailing accessing specialists.


CSEAD Corporate Science Unit – for HSE's arrangements with HSL.

Legal and Enforcement Team for legal requirements relating to access to evidence by interested parties.


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Updated 2020-12-15