2012 will increase doping temptation

Britain's anti-doping chief Andy Parkinson is "massively concerned" that the rewards on offer at the London 2012 Olympics will tempt home athletes to take performance-enhancing drugs.

Parkinson, the acting head of UK Sport's anti-doping programme, has warned the increasing availability of various banned substances means it is "only a matter of time before someone crosses the line".

With the London showpiece only four years away, Parkinson told The Guardian: "I am massively concerned, because we are at the start of four years in which kids who are now 15 or over will want to be on the start line in London, which will be the biggest thing to hit British sport in our lifetime."

He added: "The fact is that we have EPO, an increasing drug of choice for a number of disciplines, we have growth hormone, which it has been demonstrated you can get from a pub on the corner, and we have testosterone available all over the internet.

"I think it's only a matter of time before someone crosses the line.

"The rewards for success in 2012 will be absolutely enormous and at some point some will say, 'You know what, I'm going to take the risk'. What we have to do is help them make informed choices and realise that they can make it clean."