A police helicopter swooped on five anglers who had caught fish by stunning them with electric current, a court heard.

Dennis Abbott was with four other men on the banks of a Thames backwater in Abingdon during the closed season when they were caught.

Abbott, who owns Radley Fisheries, appeared before Wantage Magistrates' Court, where he admitted using electrical equipment without a permit and with intent to take or destroy fish.

But Adrian Roberts, defending, said Abbott was not fishing for financial gain but was involved in a stock survey of fish and a culling exercise to remove predatory pike.

Mr Roberts said: "Using electro-fishing equipment is a legitimate part of his business managing fisheries."

Abbott, an angler for more than 30 years manages waters for seven angling clubs in Oxfordshire, including the Bruney, near Barton Lane, where the offence took place in June last year.

It was during angling's official closed season when the five went out in a boat and used the electro-fishing equipment. They were spotted by a member of the postal workers' angling club who reported the incident and the police were contacted. By chance, a police helicopter was nearby on a training exercise. It hovered over the van being driven by Abbott and officers, using a loud hailer, ordered it to stop.

Later the fish - some with burn marks - died.

Abbott, 53, of Chiswick, west London, who also owns a shopfitting business, asked for four other similar offences to be taken into consideration. He was fined £500 and ordered to pay £1,880 costs.

No charges were brought against the other four - two men from London and two 16-year-olds from Abingdon.

After the hearing, Abbott said: "The police helicopter operation was all a bit dramatic. My heart was pounding away. I wondered what it was all about. It was all very unfortunate, but I shall continue my job managing waters in Oxfordshire."