After the hearing at the appeal court in the Hague, Warren's lawyer, Han Jahae, said there would now be an appeal to the Dutch Supreme Court - and to the European Court of Human Rights if that failed.

Second time lucky for police

Warren's conviction last June was the final chapter in a long-running Anglo-Dutch operation to smash a drugs ring smuggling vast quantities of drugs into Europe, mostly from South America.

The operation suffered a setback in 1993 when Warren was acquitted of £150m cocaine smuggling charges.

He reportedly told customs officers after that hearing: "I am going off to spend my millions and there is nothing you can do about it."

Warren: once named Britain's 461st richest man by the Sunday Times

However, last year Warren and two senior members of his gang were found guilty of trafficking in drugs and illegal possession of guns, hand grenades and CS gas canisters.

That trial heard that Warren ran his drugs empire from his homes in Liverpool and Amsterdam.

The case followed the arrest of Warren, and six others in a raid on Rotterdam docks.

The raid netted £75m worth of Colombian cocaine stashed in a container which the gang had offloaded from a Venezuelan freighter

Investigators acting with the help of intelligence from British police had tracked the container from the ship to a warehouse near the Hague.

Follow-up raids in Rotterdam and Amsterdam uncovered caches of hand grenades and automatic weapons as well as more drugs which included 1,500kg of heroin and 50kg of ecstasy - a haul worth about £100m.

'Tainted evidence' claims rejected

Warren's appeal was based on claims that telephone taps used by police in his British home to gather evidence against him were illegal under Dutch law.

Mr Jahae argued that the facts shared between the UK and Dutch authorities when they cooperated in the drugs swoop were "tainted".