Johannesburg - Global anti-doping body WADAadopted Friday far-reaching new rules against the use of banned performance-enhancers that doubles punishment for cheats as the sporting world still reels from cyclist Lance Armstrong's scandal.

World sports leaders approved rules that ban first-time intentional dopers from competitive sport for up to four years -- automatic Olympics disqualification -- though some say the measures are not tough enough.

"The board... unanimously agreed to approve and to endorse the code," said outgoing World Anti-Doping Agency (WADA) president John Fahey at a meeting in Johannesburg.

Around 1,000 delegates from the sporting world applauded at the announcement after two years of deliberation.

The revised World Anti-Doping Code follows extensive reevaluation, in a period during which the discovery of fallen Tour de France champion Armstrong's extensive doping highlighted the tough battle for clean competition.

Athletes and sports bodies had called for stricter punishment for culprits, though doping controls struggle to catch them.

Less than one per cent of checks give an abnormal result, though tests have jumped from 150,000 a year to 250,000 since WADA was created in 1999.

Armstrong was stripped of his seven Tour de France titles after using banned blood-boosting drug EPO, and global cycling union UCI will launch an inquiry early next year to clean up the sport.

The third World Anti-Doping Code governs competitive sports from athletics to football to cycling, and has been backed by powerful sporting bodies like the International Olympic Committee (IOC), world football's governing body FIFA, and governments.

While threatening strict punishment, it has been lauded for "proportionality" -- revising punishment to fit the crime in cases like the use of cannabis.

But the International Association of Athletics Federations (IAAF) has hit out at this flexibility, saying the new rules leave athletes "too many means of escape".

Four-year sanctions can be reduced to two if a caught doper denies the intention to have used a banned substance -- they do not even have to prove it.

Admitting to cheating can also reduce the sentence, or if the athlete's support personnel take the blame.

All this will "make cases more procedurally complicated, time-consuming and costly than they ought to be," according to the IAAF.

Others have said a four-year ban can torpedo an athlete's career, and that such punishment is not fair for a first transgression.

But WADA president Fahey has strongly supported the new rules on the day the organisation elects a new leader. "It is firm, but it is fair," he told delegates.

The new code is the fourth draft after 300 submissions that culminated in 4,000 suggested changes, ranging from substance to wording.

It gives WADA more teeth to police signatories' compliance.

Where previously it could only flag non-compliance, it can now order doping controls itself and investigate when countries neglect to probe doping.

Up to now, 176 countries have ratified the UNESCO convention that contains the code. It becomes law in every country that ratifies it.

"That is the fastest and most successful convention in UNESCO's history," said WADA's president Fahey earlier.

Governments and sports federations together constitute WADA's foundation board.

They have one year to implement the code before it takes effect.