A total of £675 million is owed by organised criminals ordered to pay back £1 million or more after their conviction, figures revealed.
The data, released to the London Evening Standard by the Crown Prosecution Service, relates to some 178 organised criminals.
Some still have time to pay under a deadline set by the courts, while others remain in prison as efforts to recover their criminal profits continue.
But the statistics also show that around £225 million is unlikely to ever be paid as prosecutors are unable to force repayment by some 45 of the offenders.
The Evening Standard published full details of the figures on its website. In 20 cases, the reason is that the criminals have finished their jail terms and can not be forced to attend court to account for why they have not repaid.
Another 17, who owe around £110 million, have absconded abroad, seven have been deported. Among the named criminals on the list are gangmaster Mazhar Raja, who supplied immigrant workers to Heathrow and Gatwick airports, crack cocaine crime boss Lincoln White and fraudster Craig Johnson - who reportedly bought racehorses and helicopters with his proceeds of crime.
Gregor McGill, head of CPS Organised Crime Division, said: "In the last six years we have deprived criminals, including some of the UK's most sophisticated and organised offenders, of more than £600 million. In the same period, £66 million has been returned directly into the hands of victims.
"Criminals go to extraordinary lengths to conceal the proceeds of their crimes from the police, moving assets abroad and hiding it with third parties.
"The CPS is able to confiscate these assets only once the police have located them, but the difficulties with enforcement are not an excuse for inaction. We are overcoming these challenges and the CPS is recovering more money every year.
"There are now more than 100 specialist lawyers based in teams across the country and abroad. Last year, their work led to the confiscation of more than £115 million - a record high."