David Howman, the chief executive of WADA, said the new code, which has been revamped for the first time in five years, claimed that under the new rules athletes who deliberately cheat will be dealt with even more firmly.

 

But those who dope by mistake - such as ingesting a banned substance in a helath or diet supplement - will not be treated so harshly.

 

Howman said: "Those who are determined to cheat will be treated a little firmer and those who have inadvertently taken something will be treated fairer.

 

"What it does is take advantage of some of the practical issues we encountered under the old coe.

 

"We have learned from that experience."

 

Among the changes is that the the maximum suspension have been changed from two years to four years for cases of "aggravated" doping where an athlete have been part of a large doping scheme, has used a number of substances or lied to investigators to avoid being caught.

 

Under the new code it is likely that Britain's Dwain Chambers, who took THG distributed by Victor Conte at the Bay Area Laboratory Co-Operative (Balco), would have been banned for the maximum four years.

 

The new code also offers incentives to athletes who inform on rivals who they know are also doping.

 

A "whistleblower" could receive up to a 75 per cent reduction in their sentence if they provide information that leads to others being caught.

 

But athletes who can prove that they tested positive because they took something by mistake will be given lighter sentences.

 

A number of professional players groups in Britain have criticised the new code, though, as they believe it is too stringent on their members.

 

They are particularly upset that selected palyers will have to give UK Sport their location for one hour each day to be available for a doping test - the same rule that led to Olympic and world 400 metres champion Christine Ohuruogu being banned for a year in 2006 after she was not where she was supposed to be on three occasions.

 

Welsh Rugby Players Association chief executive Richard Harry claims that his members have been properly briefed on the new system will work.

 

He said: If we start having those best players banned for two years because they are ignorant of how this system works, then how on earth is that a better scenario?

 

"I just can't agree with that."

 

But Andy Parkinson, the head of drug free sport at UK Sport, claimed that all rugby and football players were being asked to do is follow the same rules as athletes like Ohuruogu and triple Olympic cycling champion Chris Hoy.

 

He said: "What's being put in place across a whole variety of sports, including certain aspects of rugby, is the same standard that applies to Olympic sports over the past three-four years.

 

"And, yes, it is including three missed tests over an 18-month period is a one-to-two-year ban, and that comes down from the world anti-doping code.

 

"If they are new to the system we have to tailor our education programme accordingly."

 

Parkinson says the several years of experience his organisation has in drug testing under the system means athletes from sports new to the system can be helped to meet their commitments.

 

He said: "We try and apply the rules reasonably.

 

"What we want to be able to do is be able to conduct testing 365 days a year.

 

"We want athletes to be available 365 days a year and what we will do is support them as much as we possibly can and within the confines of the rules to make sure that we help them comply with that."