Thomas Mullen, who was jailed for 18 years in January for masterminding a massive £750,000 heroin smuggling operation, must pay more than £1 million or face another six years in jail.
Mullen (26), nicknamed The Boxer, was given one year to pay.
Judge Timothy King, at Snaresbrook Crown Court, east London, yesterday decided that Mullen's benefit, or the total amount he had earned form drug-dealing, was £9.1 million sterling. A confiscation order was made for the amount of just over £1 million based on police estimates of his remaining assets.
Mullen, who wore a grey sweatshirt and blue tracksuit bottoms and was handcuffed to two security officers, was told by the judge: "You will pay this money by December 21st, 1999. If you do not you will receive a further six years in jail without remission."
Mr Peter Walsh, prosecuting, described Mullen as "one of the largest heroin dealers in Europe".
Judge King gave Mullen an 18-year sentence last January after a jury found him guilty of conspiracy to supply heroin. He had masterminded the smuggling of heroin from London to Ireland.