Great Britain Olympic 400m hope Tim Benjamin has admitted missing a drugs test in 2005 due to the "strict" nature of the system.

Welsh athlete Benjamin, 25, reached the semi-finals of the 2004 Games in Athens and was fifth at the World Championships in Gothenburg in 2005. On both occasions, he was struggling with a knee injury.

Benjamin bounced back to take silver as part of the 4x400m relay team at last year's European Championships, although a virus resulted in a disappointing World Championships in Osaka last summer and he is now concentrating on an Olympic medal shot in Beijing next year.

However, he is concerned by the negative publicity surrounding British athletics following the Christine Ohuruogu affair.

Ohuruogu will also be competing in China after successfully overturning a ban for missing three drugs tests.

Benjamin believes the system is unforgiving but accepts it is necessary to keep the sport clean.

He explained: "When the public see athletics, and certain things are printed, or talked about on TV, then people can get the wrong impression.

"The best example of that at the moment is Christine Ohuruogu. Drug-testers come to your house and you also have to say where you are for an hour every day."

Revealing his own misfortune two years ago, Benjamin told BBC Sport Wales: "I was rung by my agent in 2005 to say there was a Golden League meeting in Zurich. I wasn't going to run because I was due to run in Sheffield and this was two days before.

"I told him I wasn't running but he pestered me and told me I had to run. So, 48 hours before, I flew across to Zurich but completely forgot to tell the drug-testers.

"I raced, it was on TV, and so everyone knew where I was. But a drug-tester turned up at my house, I wasn't there, so it was a missed test.

"It's a very strict system, but one I think is needed."