The British High Court has ruled that drugs cheat Liliya Shobukhova should repay in excess of £377,000 in London Marathon prize and appearance money the Russian received for the 2010 and 2011 races.
Shobukhova won the famous marathon in the English capital six years ago and finished second 12 months later, picking up £377,961.62 as a result of those performances.
The 38-year-old was banned by the IAAF last August following abnormalities in her biological passport, with her results from October 9 2009 onwards consequently annulled.
London Marathon organisers pursued a case to reclaim the money awarded to Shobukhova, plus costs, and the British High Court ruled in their favour.
Nick Bitel, chief executive of London Marathon Events Ltd, said: "The next step is to get the judgment enforced in Russia. It will be a long and difficult process but we will pursue it as we are determined that cheats should not benefit.
"Any money we get back will be redistributed to the athletes that Shobukhova cheated out of their rightful dues.
"We are determined to make marathon running a safe haven from doping. We will continue to do everything we can to ensure cheats are caught and do not benefit from cheating.
"In addition to testing operated by the IAAF and national federations, the Abbott World Marathon Majors has set up one of the largest private testing pool of athletes in sport, with 150 competitors being tested out of competition a minimum of six times a year for their unique athlete biological passport."