The police want information from me about a client or wish to access a file. Can I assist them?

You must maintain confidentiality and legal professional privilege. Unless you have the client’s authority to do so, or one of the exceptions applies, you should not disclose any confidential or privileged information to the police, even informally. Whether the police could get a search warrant or subpoena you is immaterial.

For the exceptions to confidentiality see s 3 of the Solicitors Rule 2007.