The World Anti-Doping Agency (WADA) officially extended the rule to all Olympic sports on January 1 and it has since attracted heavy criticism from tennis, football and rugby players who have claimed that it places too much pressure on them.

 

But Radcliffe, the world record holder for the marathon and a long-time anti-drugs campaigner, claimed it is necessary to ensure that sport is kept clean.

 

The Bedford runner said: "We are all committed to doing what we can to keep our sport clean.

 

"That means scarifices by clean athletes but we those running anti-doping understand we are human and are there to help.

 

"For truly international fair testing everywhere we need this."

 

Under the new WADA code, athletes must give three months' advance notice of where and when they can be located for testing one hour a day - seven days a week, between 6am and 11pm.

 

The information is registered online and can be updated by e-mail or text message.

 

Radcliffe said: "Obviously sometimes it can be a hassle and something I always have to remember but a small price to pay to work towards clean sport."

 

Radcliffe, a member of the International Association of Athletics Federations (IAAF) Athletes Commission, has never been shy to let her feelings known about those she suspects of cheating.

 

At the 2001 World Championships in Edmonton she and team-mate Hayley Tullett held up a banner in protest at Russian runner Olga Yegorova being allowed to compete despite having tested positive on the eve of the event for the blood-booster Erythropoietin (EPO) only to escpae a ban on a technicality.

 

Nadal and Andy Murray, Britain's top-ranked tennis player, have both hit out at the new system but WADA insist they will not change it.

 

Blanka Vlasic, Croatia's world high jump champion, also backed the rule.

 

She said: “I understand that it is necessary for IAAF to know where the athletes are at all times because there is no other way in this moment to fight the doping problem.

 

"Especially this 60 minute slot is a good idea, because each of us could tell with 99per cent when are we at home for sure.

 

"In this way we would be able to avoid inconveniences with anti-doping controls.”