County Hall was filled with a pungent smell today as Oxfordshire County Council trading standards officers examined a haul of suspect fish.

Martin Woodley and his colleagues have collected hundreds of packets of fish from people who claimed they were bullied into buying seafood by rogue door-to-door fishmongers.

Mr Woodley said his team had been contacted by at least 15 people who had fallen foul of the salesmen in Oxford, Witney, Chipping Norton and Banbury.

He said the victims, who were mainly elderly and living alone, paid between £350 and £400 for fish without knowing how much and what type of fish they were really getting.

He added: "We have got a considerable number of fish pieces in packets, which have no labelling and we cannot identify which species they are.

"The seller gave specific names like sea bass, hake or cod."

Nigel Strick, head of trading standards, said: "In some cases the seller pretty much forced his way through the front door. He was taking cheques. He was bullying and when people made any sort of move to say 'I do not want that amount' he was quite menacing."

A 36-year-old man has been arrested in Banbury on suspicion of fraud and has been bailed to appear at St Aldate's police station, Oxford, on Friday.