British bookmaker William Hill will pay £6.2m as a penalty for breaching anti-money laundering and social responsibility regulations, the UK's Gambling Commission said today. 

Failure in the company's checks meant that ten customers deposited large sums linked to criminal offences, resulting in gains for William Hill of around £1.2m, it said. 

"This was a systemic failing at William Hill which went on for nearly two years and today's penalty package - which could exceed 6.2 million pounds - reflects the seriousness of the breaches," the Commission said. 

William Hill did not adequately seek information about the source of customers' fund or establish whether they were problem gamblers, the regulator said. 

One customer, who earned about £30,000 a year, was allowed to deposit £541,000 over 14 months with no probing other than a verbal conversation, it said. 

The customer was funding his gambling habit by stealing from his employer. 

Another customer, who also had an annual salary of about £30,000, gambled £654,000 over nine months with no checks on the source of funds, it said. 

William Hill said it had changed its policies and increased investment in anti-money laundering. 

"We are fully committed to operating a sustainable business that properly identifies risk and better protects customers," William Hill's chief executive Philip Bowcock said. 

"We will continue to assist the commission and work with other operators to improve practices in the areas identified," he added. 

The bookmaker will pay £5m for breaking regulations, the commission said.

Of the £1.2m the company made from the bets, £790,000 pounds will be returned to victims identified who had money stolen and more than £230,000 will be paid to charity. 

Rival UK gaming company 888 Holdings was fined a record £7.8m last year for failing to protect vulnerable customers from addictive gambling.