The global drug smuggling gang - whose leading member has been jailed for nine years - is thought to have laundered hundreds of thousands of pounds through race courses.

Now the sport's ruling body, the Jockey Club, has called for tighter regulations over betting to prevent any possibility of infiltration by criminals.

The revelations of the activities of the Wright gang underline racing's vulnerability to corruption by criminals

Christopher Spence

Its disciplinary committee is also expected to consider action - including the possible exclusion from all racecourses - of a number of people involved in the cocaine smuggling trial.

Hilton John Van Staden, a 52-year-old South African, pleaded guilty on Friday at Bristol Crown Court to conspiracy to import drugs.

Cash-rich world

Fifteen other people have been convicted worldwide with sentences totalling 206 years.

One alleged gang member Brian Wright is still at large, believed to be in Cyprus.

Racing sources say large sums of money passed through racing circles by the gang would not have been noticed in the cash-rich world of on-course betting.

Christopher Spence, the Jockey Club's senior steward, said: "The revelations of the activities of the Wright gang underline racing's vulnerability to corruption by criminals and the potential of betting as a vehicle for money laundering."

But he warned that the situation should be kept "in perspective".

Most of the gang's activity happened over a period of years ending in the late 1990s, he said.

Since then a series of steps have been taken to stamp out corruption, including spending more than �17m a year to protect the integrity of the sport.

He said there was "no evidence that criminal activity on anything like a similar scale is operating today".

'Serious malpractice'

But the Jockey Club's Integrity Review Committee is reconvening to look at all the latest information and see if tougher measures still need to be taken.

Mr Spence said the greatest protection for the betting public would be "firmer regulation of betting".

"We welcome the government's plans for reform of the gambling laws published in March and urge that the necessary legislation is introduced as soon as possible," he said.

In the meantime, he said the Jockey Club would be announcing its own action next week.

Those facing action are believed to include Mr Wright.

'Tips'

The Jockey Club gave a file on him to police, before he was questioned about alleged doping and race fixing in 1998 but he was released without charge.

During one of the Operation Extend trials there were claims that gang members received tips from people within the racing world.

This too will be investigated by the Jockey Club and anyone found guilty of such practice will face action.

The racing body issued warnings with National Hunt jockey licences in 1999 urging trainers and jockeys not to accept favours from anyone who could put them in a "compromising position".