Boris Johnson has rejected suggestions the London 2012 Olympics have been sabotaged by claims of wide-scale "state-sponsored" Russian doping.
The London mayor insisted Team GB beat Russia fairly without the "assistance of any performance enhancing drugs" as he voiced his concerns about the "very serious" allegations.
A report by an independent commission set up by the World Anti-Doping Agency (WADA) revealed 1,417 samples were deliberately destroyed on the orders of the director of Russia's drug-testing laboratory.
It added this official took cash to cover up positive tests, plus there was intimidation of officials by undercover officers from the Russian secret service FSB.
Russia faces being banned from the Rio 2016 Olympics after the investigation, with the commission's chairman Richard Pound believing London 2012 has been "sabotaged" by the presence of Russian athletes with suspicious doping profiles.
Team GB finished third in the medal table at the Olympics three years ago, one place ahead of Russia thanks to a haul of 29 golds.
After arriving in Jerusalem as part of his trade mission in Israel and the Palestinian territories, Mr Johnson said IAAF president Seb Coe and the authorities must be supported in their efforts to "clear up" the sport.
He told ITV News: "I think it's very serious if there was corruption, if there was drug-taking and doping in any athletic competition.
"I don't think it frankly detracts at all from the success of London 2012 Olympic and Paralympic Games but we must hope that Seb Coe and the authorities in international athletics clear it up as soon as possible."
Asked if the 2012 event was sabotaged, the Conservative MP said: "No not at all. Look, it was a very successful Games, one of the greatest Games ever - the greatest Games ever.
"There's been some very serious allegations made against the Russian team by Wada.
"They need to be properly checked out now and I think what needs to happen is we need to get behind Seb Coe in his efforts to clear up international athletics."
He added: "The Russians were only a small representative team and, after all, as far as I can remember we beat the Russians fair and square without the assistance of any performance enhancing drugs."