Scots trawler tycoon Tom Nicholson was ordered yesterday to pay £500,000 after his company admitted exceeding fishing quotas.

A judge at Newcastle Crown Court imposed the seizure under the Proceeds of Crime Act after Nicholson from Annan, Dumfriesshire, admitted a total of 26 breaches by his company of EEC regulations which control catches of specified species of fish.

He was also fined £27,000 by Judge David Wood after being busted in an18-month probe into the trade in "black fish".

The crackdown came between January 2004 and July 2005 and last year six of Nicholson's skippers including his son Chris were fined for a variety of offences. The investigation was led by the government's Marine and Fisheries Agency which was probing over-fishing.

TN Trawlers and its fleet fish in the Solway Firth and the south of England.

The charges relate to more than 50 trips where catches were not declared.

The court was told that if Nicholson, 44, is unable to raise the £472,000 within six months he could face up to three years in jail.

The judge told Nicholson that a message had to be sent out to people in the fishing industry that breaking the rules would not be tolerated and would be met with large penalties. The judge added: "It is well-known that fishing stocks around the UK and European countries are seriously depleted and some stocks area threatened with extinction.

"Whether you agree or disagree, some control has to be exercised and that control has to be enforced."

He described the offences as serious and said that failing to declare what had been caught endangered the livelihoods of those fishing honestly.

Nicholson is reputed to be worth millions, but Bertie Armstrong, the Scottish Fishermen's Federation's chief executive, said: "There is no doubt this is a significant penalty and will affect his business.

"No-one can stand that kind of smack without it hurting. But he got what was coming to him. We can put our hands on our hearts and say we have a compliant industry and we hope this will help to keep it that way."