West Ham’s shirt sponsor Betway has been hit with a record £11.6 million penalty package for a series of social responsibility and money laundering failings.

The Gambling Commission said that in one instance the operator failed to carry out source of funds checks on a “VIP” customer who deposited over £8 million and lost more than £4 million during a four-year period.

Betway also failed to carry out effective social responsibility interactions with a customer who deposited and lost £187,000 in two days.

An investigation found that as a result of a lack of consideration of individual customers’ affordability and source of funds checks, the operator allowed £5.8 million of money to flow through the business which has been found, or could reasonably be suspected to be, proceeds of crime.

The majority of this money will now be divested and returned to victims, the Gambling Commission said.

The regulator probe also revealed inadequate management oversight and investigations into responsible personal management licence holders are ongoing.

Richard Watson, executive director at the Gambling Commission, said: “The actions of Betway suggest there was little regard for the welfare of its VIP customers or the impact on those around them. As part of our ongoing programme of work to make gambling safer we are pushing the industry to make rapid progress on the areas that we consider will have the most significant impact to protect consumers.

“The treatment and handling of high value customers is a significant piece of that work and operators are in no doubt about the need to tackle the issue at speed.

“We have set tight deadlines for when we expect to see progress and if we do not see the right results then we will have no choice but to take further action. This case highlights again why progress needs to be made.”

The Betway case is the largest penalty package ever in the UK.