It is illegal to ‘handle salmon in suspicious circumstances’
In the UK it is illegal to handle a salmon under suspicious circumstances’. This is an offence under the Salmon Act of 1986. The law was actually designed to prevent people selling fish gained through illicit means – rather than those holding them, well, in a suspicious way.
Apparently, a five-hour House of Lords debate about the issue in February 1986 decided on the wording and thought that it would protect unwitting people from the then-in-place wider law of “possessing salmon which have been illegally taken, killed or landed”.