The rise was linked to a crackdown on money laundering and unfair practises.

The Commission's new enforcement report published on Thursday summarises investigations and best practice, asking gambling chiefs to “lead a culture of compliance”.

William Hill received a fine of £6.2 million in February for breaching anti-money laundering regulations and social responsibility policies. Just last week, 32Red were also fined £2 million for fail to protect online gamblers.