|DISGRACED: London Marathon 2010 winner, Russian Liliya Shobukhova, receiving a two-year doping ban from Russia's athletics federation in 2014.|
SEVEN London Marathon champs in the past 12 years recorded dodgy blood tests, it has emerged.
The shock figures equate to almost 30 per cent of champions in the 24 men’s and women’s races.
It sheds new light on potential drug cheating by top athletes across the globe.
The “alarming” data, revealed today by the Sunday Times newspaper, refers to races in London, Boston, Chicago, New York, Berlin and Tokyo.
London Marathon chief executive Nick Bitel told how race organisers are “very concerned” by the broadsheet’s claims.
According to “expert analysis”, the newspaper says one in four marathon winners should have been investigated over potential blood doping.
And the runners whose results were believed to be “suspicious” pocketed more than £4milion in cash prizes.
In London alone, seven wins, six second places and seven third places were by competitiors “whose blood tests were deemed suspicious”.
The confidential figures are owned by the International Association of Athletics Federations (IAAF).
But it was leaked to the Sunday Times by a whistle-blower.
Mr Bitel said: "We believe there are people in our sport who are cheating and everyone has a part to play to protect those who are not.
"We continue to be at the forefront of anti-doping measures for marathon runners as we are determined to make marathon running a safe haven from doping.
“But we cannot do it all on our own and rely heavily on the IAAF.
"We are therefore very concerned by the allegations made in the Sunday Times today and we will be discussing the implications of the allegations with the IAAF."
London Marathon organisers have vowed to take legal action to recover prize money awarded to Russia's Liliya Shobukhova, whose competitive results as of October 9, 2009 have been disqualified by the IAAF.
Shobukhova finished first and second, respectively, in the 2010 and 2011 London Marathons.
She had been the second fastest female marathon runner of all time behind Paula Radcliffe before receiving a two-year doping ban from Russia's athletics federation in 2014.
The Sunday Times also published anti-doping blood test data from athletes including double Olympic champion Mo Farah has vowed to prove he is a clean athlete.
He is one of eight British competitors defying athletics authorities by agreeing for blood test data - which show results fall within the normal expected range - to be made public by the newspaper.