Section 35 - Law enforcement

Challenge a refusal under FOISA section 35 - the authority says disclosure would prejudice law enforcement

What this exemption means#

The authority is saying that disclosing the information would, or would be likely to, substantially prejudice one or more law enforcement functions or activities. Section 35 covers a wide range of purposes including the prevention and detection of crime, prosecution of offenders, tax assessment, immigration controls, and various regulatory functions.

This is a qualified exemption, so the authority must pass the public interest test even if the exemption itself applies.

What the authority must show#

Section 35(1) lists several different law enforcement functions that can be protected:

Section 35(1)(a) - the prevention or detection of crime
Section 35(1)(b) - the apprehension or prosecution of offenders
Section 35(1)(c) - the administration of justice
Section 35(1)(d) - the assessment or collection of any tax or duty
Section 35(1)(e) - the operation of immigration controls
Section 35(1)(f) - security and good order in prisons and other places of lawful detention
Section 35(1)(g) - prejudice to a public authority’s functions for specific regulatory purposes listed in section 35(2)
Section 35(1)(h) - civil proceedings arising out of investigations for section 35(2) purposes

For any of these, the authority must:

Identify which specific subsection they are relying on
Explain the specific prejudice that disclosure would cause to that function
Show the prejudice would be substantial - real and of demonstrable significance, not marginal or speculative
Show the prejudice is likely - there must be at least a significant probability, not a remote or hypothetical possibility
Show the information is less than 100 years old
Carry out and explain a public interest test

Things to check#

Did they specify which subsection? Section 35 covers many different law enforcement functions. The authority should identify exactly which one is relevant. A vague reference to “law enforcement” is not good enough - the specific function must be identified.
Did they explain the specific harm? The authority must show a genuine link between disclosure of this particular information and the claimed prejudice. A general argument that law enforcement information should be withheld is not sufficient.
Is the prejudice substantial? The damage must be of real and demonstrable significance, not merely marginal. There must be at least a significant probability that the harm would occur.
Is this about an active or historical matter? The passage of time is relevant. If the information relates to a concluded investigation, completed prosecution, or historical matter, the case for prejudice is significantly weaker. The authority would need to explain why disclosure would still cause harm.
Is the authority’s function actually a law enforcement function? For sections 35(1)(g) and (h), the authority must show it was carrying out a function for one of the specific purposes listed in section 35(2), such as ascertaining whether someone has broken the law, investigating improper conduct, or exercising regulatory functions.
Did they consider the public interest? There is often a strong public interest in transparency around law enforcement, particularly where there are concerns about how public authorities exercise their powers. The public interest test must weigh both sides.

Use the interactive tool#

Answer the questions below to check whether section 35 has been properly applied to your request.

What the evidence shows

Arguments that have supported disclosure

In cases where the public interest test favoured disclosure, these themes appeared most often.

Transparency of regulatory functions The public has a right to understand how regulatory and law enforcement bodies carry out their functions
Accountability and scrutiny Public authorities should be accountable for how they exercise their enforcement and regulatory powers
Understanding how concerns are handled The public has an interest in knowing what concerns are raised and how they are investigated and addressed
Scrutiny of public spending Where enforcement or audit functions involve public funds, there is a public interest in understanding how they were used

What authorities typically argue

These are the arguments authorities most commonly make when withholding information under this exemption. Knowing them helps you prepare a stronger case.

Prejudice to crime detection Authorities argue that disclosure could help criminals evade detection or undermine the ability to investigate offences
Protecting confidential sources People who report concerns or provide information need confidence that their identity will be protected
Protecting ongoing enforcement action Disclosure could prejudice current or planned enforcement, prosecution, or disciplinary action
Maintaining cybersecurity Disclosing security details could expose systems to attack and endanger data or services
Deterring future complaints and cooperation If complainants or informants fear being identified, they may stop coming forward, undermining the enforcement function

Factors that tipped the balance

In decisions where the Commissioner ordered disclosure, these factors were decisive.

Claimed harm was overstated The Commissioner found the authority's arguments about prejudice were not persuasive or not applicable to the specific information
Authority failed to evidence the harm The authority could not demonstrate how disclosure of this particular information would enable the prejudice it claimed
Information was not actually sensitive The information was less sensitive than the authority argued, and its disclosure would not cause the harm required to engage the exemption
Partial disclosure satisfies public interest Some information could be disclosed without causing the harm associated with disclosing the whole, allowing the public interest to be served

Based on published decisions of the Scottish Information Commissioner. You can browse the decisions on the Commissioner's website.