Mo Farah leads athletes who want anti-doping results made public

The London Marathon chief executive says his organisation is doing "more than anyone else" to ensure athletes are not doping.

Nick Bitel was speaking to ITV News about allegations made by the Sunday Times about drug test data from 2001 to 2012.

London Marathon chief executive Nick Bitel has said race organisers are "very concerned" by allegations in the Sunday Times that seven winners in a 12-year period recorded suspicious blood scores.

The newspaper 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 £3million in prize money.

The head of world athletics has said any suggestion his organisation had been negligent in drug testing was "laughable".

Lamine Diack, President of the International Association of Athletics Federation, told Reuters there was "no evidence" anything of the sort had taken place.

"There are allegations made. We want to look into them seriously because to say that in athletics between 2001 and 2012 we did not do a serious job with tests is laughable," he said.

The Sunday Times (£) reported obtaining secret data from the IAAF suggesting more than a third of medals had been won by athletes with "suspicious" blood test results.

Sports Minister Tracey Crouch said "everyone involved in sport must work together" following fresh claims of doping by Olympic athletes.

Jessica Ennis-Hill has called on the IAAF and the World Anti-Doping Agency (Wada) to address the problem of doping after fresh claims of cheating.

"It is never good to hear of new possible doping offences in my sport, but if we are to stop a few athletes thinking cheating is acceptable, we have to explore all information that comes to light, however damaging it is for the sport as a whole", she said.

According to the Sunday Times (£), leaked data reveals that more than a third of medals - including 55 golds - have been won in endurance events at the Olympics and world championships by athletes who have recorded suspicious tests.

It is also alleged that a top UK athlete is among seven Britons with "suspicious" blood scores, while 10 medals were won at the London 2012 Olympics by athletes who have reportedly recorded dubious test results.