The integrity of the London 2012 Olympics could be shattered by the enormous threat of illegal gambling rings trying to fix results, the Olympics minister said on Sunday.

Event fixing could play a very real part at the Olympics, Hugh Robertson said, adding that he was trying to convince other governments to take the threat seriously to avoid a scandal which could scar the reputation of the Games.

We know that there are enormous illegal betting syndicates in both the Indian subcontinent and across the far east, Robertson told Sky News.

We know that pressure is very often exerted on athletes and indeed athletes' families. We know it's out there.

It's very difficult in cultures where they don't admit that gambling takes place, so it all happens behind closed doors, in back rooms and so on and so forth, it all happens illegally. It's very, very difficult to police that.

Illegal betting and event fixing have not been detected at previous Olympics, according to authorities, but Robertson's ramping up of the rhetoric reflects a concern that not enough is being done across the world to clamp down on the activity.

A joint intelligence unit, comprising the International Olympic Committee, Britain's Gambling Commission watchdog and the police, will operate during the 2012 Games, drawing on information from betting firms, national Olympic committees and Interpol.

The IOC, which has banned athletes and their entourages from placing any bets during the Games, has issued advice to athletes and officials and will set up an email hotline for reporting suspicious activity.

The IOC used betting early warning systems during the Beijing 2008 and the Vancouver 2010 Olympics and neither Games showed anything suspicious.

But IOC president Jacques Rogge has said there is a danger gambling rings will penetrate the Games in the future.

Robertson said he was confident that sufficient action had been taken to minimise the threat in Europe, through information sharing and co-operation between organised crime agencies, police, gambling bodies and sports organisations.

It's not really an expensive thing, it's more about setting a good example and convincing others that this is a threat that needs to be taken seriously, he said.

(Reporting by Matt Falloon, editing by Justin Palmer)