These may be the most tested Olympic Games in history, but New Zealand's highly respected international anti-doping supremo David Howman has stopped short of labelling them the "cleanest".

Howman, the now Canada-based former Wellington lawyer, is the secretary general of the World Anti-Doping Agency (Wada) and yesterday in London he faced the world's media to explain the scrutiny that will go on the athletes of these Olympics.

Howman and his colleague, Wada president John Fahey of Australia, spelt out a testing process in London that is the most diversified and targeted in the history of the anti-doping programme, including a recent breakthrough in the detection of the problematic Human Growth Hormone (HGH). 

They also spoke glowingly of the IOC's programme that was seeing samples from as far back as 2004 re-tested under modernised protocols, and continuing to unearth doping cheats.

"Someone who thinks they're home free after London, might need to hold their breath for the next eight years," said Fahey.

But the New Zealander's response was pointed to say the least when asked whether, given a programme that had unearthed 107 drug cheats in summer Olympic sports over the last six months, and conducted 71,649 tests in that time, these would be the "cleanest" Games ever.

"You know who you have to ask that question to - the the 10,000 athletes who are here because the responsibility has  got to be firmly on their shoulders to prove to you and the world they've come here clean," said the razor-sharp Howman.

"All we can say is the programme is in place, the rules are in place and the protocols are in place, and you couldn't expect more from anybody who is in charge of managing the anti-doping programme. But the responsibity must rest with the athletes and their advisors."

Someone asked Howman for a personal view based on the best part of a decade at the upper end of the anti-doping spectrum.

"I'm too much of a cynic," responded the anti-doping campaigner with a wry smile..

Howman also played a straight bat to questions over whether they would be frustrated if an athlete with such a clouded doping history as US sprinter Justin Gatlin triumphed at these Games.

"If they're eligible to compete, they're eligible to win. It's the only answer we can give. We don't have emotions, our job is to make sure the  anti-doping programme is adhered to."

Asked about any particular concerns heading into these Games, Howman said there were always issues around "cocktail" or "designer" drugs, but that the growing use of intelligence to target suspicious athletes helped in this area.

"We are receiving information from a number of people and we use that. In terms of what we might be worried about, it's the same old stuff. You worry about EPO (Erythropoietin), you worry about micro-dosing of EPO, you worry about synthetic use of human growth hormone and synthetic use of testosterone, and the latter two are difficult to detect because the human body produces them naturally.

"You've got to be on alert for that and you've got to make sure people in laboratories are on the alert."

Howman also confirmed a new marker test was now available for HGH that had a significantly longer detection window. 

It can be utilised alongside the pre-exisiting test.

"It was approved only a matter of weeks ago, and has been subjected to research and review for nearly 13 years. It underwent a really strong period of scrutiny."

The Kiwi also stood by recent comments in which he felt as many as one in 10 athletes at these Games could be using illegal drugs of some description.

"The fear is going to be there forever," he responded.

"One in 10 could be the case, or it could be one in 20. We always have to respect the fact there will be some athletes out there prepared to take shortcuts. We must remain vigilant, therefore we must repond to that fear."

With Howman at the helm, the good fight continues to be fought.

- © Fairfax NZ News