The rules governing controversial betting machines in High Street bookmakers will be reviewed by the Government.

Fixed-odds betting terminals (FOBTs), which have been dubbed the "crack cocaine" of gambling, allow punters to stake up to £100 every 20 seconds.

The review could see that maximum stake reduced to as little as £2 if the machines are found to be causing harm.

A Department for Culture, Media and Sport spokesman said: "We will continue to monitor the effectiveness of existing gambling controls and will take further action if necessary."

Critics of the machines have claimed they are based disproportionately in poorer areas and can be used by criminals as a way of laundering dirty cash.

In April, councils called for the £100 maximum stake on FOBTs to be brought in line with other gaming machines on the high street, where the top stake is £2, or casinos where it is £5.

A spokesman for the Association of British Bookmakers said: 'We will continue to work with the Government, the Gambling Commission and charities on measures that will help problem gamblers.

"The triennial review should be evidence-based and not unfairly penalise the majority who gamble responsibly and enjoy their leisure pursuit.

"While 99.5 per cent of the adult population gamble responsibly, for those that do develop gambling problems it is rarely, if ever, limited to just one form of gambling.

"Fixed-odds betting terminals have been played in betting shops for over 15 years and yet problem gambling levels have remained relatively stable before and after their introduction, at 0.5 per cent of the population.

"High street betting shops, unlike other gambling outlets with gaming machines, do not sell alcohol, or open 24 hours a day and we don't advertise our gaming machines. Further, our customers can set limits on the amount they spend and the time they play for.

"In July this year, we doubled the number of responsible gambling messages targeted at customers with mandatory warning alerts being displayed after 20 minutes of play or £150 spent.

"We have also voluntarily introduced a range of responsible gambling measures in the last two years that go far beyond what is required by law. We will continue to build on our work to date and develop new responsible gambling measures to help the minority who do get into problems and ensure that they seek the help that they need."