The British newspaper, working together with German TV company ARD, has published fresh allegations following its analysis of drugs test data from 2001 to 2012.

It said the winners of 34 major marathons around the world - one in four - during the period should have faced censure or investigation because of their test results, with those athletes collecting more than $5 million (£3 million/€4 million) in prize money.

London was said to be the worst affected, with seven wins, six second places and seven third places out of 24 men's and women's races allegedly involving suspicious blood scores.

"We believe there are people in our sport who are cheating and everyone has a part to play to protect those who are not," Bitel said in a statement.

"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."

Appearing on BBC Radio Five Live's Sportsweek programme, Bitel criticised the IAAF, saying that although the London Marathon pays for its own drugs testing, it does not administer the programme and does not get to see the results, meaning organisers had been unaware of the suspicious blood data.

"We are disappointed," he said.

"We're doing more than anybody else to fight doping in our sport.

"We were the first people to call for blood testing and in fact we're still probably the only event in the world that blood tests all our athletes.

"What this story is really about is the IAAF's failure to take effective action.

"Those athletes that have been caught...have only been caught because of the tests at the London Marathon.

"The IAAF needs to do more to stop people from starting [a race] that have blood values that are out of normal range.

"What is concerning is that we're never told these results even though we're paying tens of thousands of pounds to get these athletes tested."

Not all of the tests studied by the Sunday Times were taken at the time of the marathons in question.

London is a member of the World Marathon Majors alongside the events in Berlin, Boston, Chicago, New York City, and Tokyo - the other races included in the latest part of the Sunday Times investigation.

In March, the six-race marathon body announced a new anti-doping scheme which Bitel hopes can take the fight against doping to the next level, although he again criticised the IAAF for not taking the lead.

"We've agreed with the IAAF that we are going to instigate the largest ever anti-doping scheme which will involve hundreds of out-of-competition tests for athletes across the world," Bitel said.

"That's something that I suspect the IAAF should have been doing but we're not prepared to wait, so we along with our colleagues from the other marathons around the world are going to be doing this and paying for it entirely on our own."

Last week the Russian Liliya Shobukhova was stripped of her three Chicago marathon titles and 2010 London win, with all her results from 2009 onwards annulled. Shobukhova was banned in 2014 due to irregularities in her biological passport.

The London Marathon had already announced it was beginning legal proceedings against Shobukhova in an attempt to recover prize money, which Bitel said on Sportsweek totalled around £500,000 ($800,000/€700,000).

The leaked database obtained by the Sunday Times contains more than 12,000 blood tests from 5,000 athletes.

The results have been analysed by experts Michael Ashenden and Robin Parisotto.

In response, eight British athletes including Mo Farah and Jo Pavey have said they will make their own blood data public.

"Athletes who have got nothing to hide won't fear having their results in the open," Bitel said.

"But the problem is there are occasions when a value can be a little high and it doesn't indicate that person has been cheating.

"It's so difficult.

"Sometimes that can happen and it can be taken out of context.

"You do need to see a totality of results, but in the case of what the Sunday Times has revealed there are clearly values there that should concern people.”

Meanwhile UK Anti-Doping (UKAD) chief executive Nicole Sapstead said in a statement: “UK Anti-Doping advises any athlete that it is their choice as to whether to share personal medical information, which has been collected during the anti-doping process.

“UKAD will never disclose or discuss individual athlete data or personal information.

"We must uphold and protect an athlete’s right to privacy.”

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