Only 77 governments have signed a UN-backed anti-doping convention

Of the 191 countries that agreed to implement a United Nations-backed anti-drugs convention in 2003, only 77 have so far done so.

New World Anti-Doping Agency (Wada) chief John Fahey wants the other 114 to do so as soon as possible.

"We need universal ratification of the Unesco convention," said Fahey.

"It would give the anti-doping movement the tools required to tackle some of the major issues, which are outside the purview of the sporting movement.

"Without government support we cannot address many issues at national level, including the production, possession and distribution of banned substances.

Drug cheats are more likely than ever at an Olympic Games to be found out New Wada chief John Fahey

"The sad reality is that many governments are yet to outlaw such practices."

Despite his frustration at the slow speed many governments were moving at when it came to the fight against drugs in sport, he said things were constantly improving.

Speaking to the BBC, he said Wada had been working with the International Olympic Committee (IOC) and the Chinese organisers to make sure the anti-drugs framework would be stronger than ever at the upcoming Beijing Olympics.

But he added: "Does that lead to an outcome which will be perfect? I would love to think it did, but I would simply say here, I hope cheats don't make it in the first place.

"If they do, they're more likely than ever, at an Olympic Games, to be found out."

And he insisted that the Wada-led struggle against doping would only intensify.

"I think as we move forward past these Games, towards London, there is every reason to believe that we're getting better," he said.

We have to think like cheats to catch cheats - I won't tell you how we do that but I want athletes to be really worried that they're going to get caught Wada director general David Howman

Wada director general David Howman confirmed that leading athletes competing in the Beijing Olympics would be targeted for pre-Olympic, out-of-competition testing by an International Olympic Committee anti-doping task force.

"We are working with the IOC to help them look for appropriate targets and we will give them advice on who to target," said Howman.

"We have to think like cheats to catch cheats. I won't tell you how we do that. But I want athletes to be really worried that they're going to get caught."

Fahey, a former Australian finance minister, took charge of Wada in January, replacing former president Dick Pound.

He is due to hold meetings with sports minister Gerry Sutcliffe on Thursday and Fifa president Sepp Blatter on Friday.

On Wednesday he paid tribute to Wada's efforts in the past but warned against complacency.

"The fight against doping is forging ahead on a firm footing and a solid foundation," Fahey said.

"We should be wary of satisfaction with the status quo, however, because the status quo is not sufficient to tackle the harsh realities of doping."