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:

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

Entitlement to access

Scope of access

Supervision and liaison arrangements

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:


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


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.


Updated 2020-12-15