Just to add some clarity to what a private/club bailiff can do if he wishes to carry out the instructions of his club or fishery owner, Be warned it is extremely dangerous legal territory for a private person to contemplate a search of any individual or make any examination or seize equipment unless that person is authorised in writing by specific legislation.
Club Keepers can ask for membership cards and or ensure that club rules only are being observed and nothing more in reality.
The only exception is where a licence holder produces his licence to another angler and can ask to see another anglers licence by virtue of section 35 (2) and should an angler refuse such a request, then an absolute offence is committed.
The only authorised persons who can carry out the task of searching or making any examination or seizure formally IS a Water bailiff (Fishery Inspector) appointed by the Environment Agency and or on behalf of the Minister of Fisheries and a Police Constable under powers deemed and granted by Sections 31 and 36 of the Salmon & Freshwater Fisheries Act 1975 and such authorised persons are defined by section 41 of the Act.
A person can only be arrested by these officers for illegal fishing at night under section 34 ( presently being reviewed)
As Mike Parker stated, such an action could lead to a " Breach of the Peace" and the offending searcher/examiner may well end up, not only injured but later arrested having committed a whole bin load of offences whilst having breached an individuals " Human Rights"
The impact of such an action may well be tested in the criminal courts after the event, however the follow on in the Civil court would be inevitable and the financial consequences for a controlling club/syndicate if found culpable would be devastating if not ruinous.
The Moral of this warning is - all angling clubs should consult a legal advisor before arming an poorly advised angler to do a job that is a minefield waiting to go up like a mexican wave.
The best advice that can be given is, if you see what you suspect is someone committing a fishery offence, then ring the EA at the telephone number on the rod licence and ask for bailiffs to attend ASAP, if people are removing fish, then call the police as well and give them as much information as possible about cars, numbers of people involved etc, The Police can then deal with the matter as an incident within the meaning of The Theft Act 1968.
Another offence that rears it's head very often is the one of Angler Apathy, it's not legislated for but so many guy's breach it by ignoring problems_ " Enough Said !!"