Humphrey Kayange, who has captained Kenya for three years, takes over from former Samoan captain and World Series winner Uale Mai to become the sport's second anti-doping ambassador.

"I am hugely proud and honoured to take up this role," said Kayange, who works as a laboratory analyst at the Kenya Bureau of Standards in Nairobi.

"Rugby sevens is hugely challenging both physically and mentally and across the board the players from all nations are now reaching incredible levels of fitness.

"Proudly, I can say that we do so through sheer hard work, determination and a will to win in front of the hundreds of thousands of fans who come to watch us all around the world.

"We must remain vigilant, though, and continue to educate the younger players in particular who can make such a mark so quickly in rugby sevens."

Each year the IRB raises the number of tests carried out on international rugby players.

In 2009, 1,293 tests were undertaken, 360 in-competition and 933 out-of-competition across both men's and women's, in 15s and rugby sevens.

Of those, 604 tests were carried out in relation to the Rugby World Cup Sevens in Dubai which resulted in no positive findings.

The IRB has been commended by WADA, the World Anti-Doping Agency, for both its testing programmes and educational campaign.

"The IRB and its member unions operate a zero-tolerance policy towards drugs cheats in rugby and this record testing programme, combined with over 4,000 controls administered by our member unions and their national anti-doping agencies, underscores our collaborative commitment in this critical area of the game," said IRB anti-doping manager Tim Ricketts.

"While rugby has been at the forefront in the fight against doping in sport, it is important that we continue to develop policies that put the player first and ensure that our players have access to the best educational framework in the area of anti-doping.

"We are delighted to bring on board someone of Humphrey's calibre and experience.

"He's well respected among the players and we're sure he will continue to do his very best for rugby both on and off the pitch."