Personal management license holders at Casino 36 must undertake extra training as part of a £300,000 ($376,155) penalty levied by the Gambling Commission for anti-money laundering and social responsibility failures.
Included in the settlement, Casino 36 will divest £147,741 and make a payment of £152,259 in lieu of a financial penalty.
An investigation by the regulator showed the operator did not ensure sufficient customer enhanced due diligence, source of funds and source of wealth checks were carried out for 33 customers.
Casino 36 also failed to satisfy Gambling Commission requirements for customer interaction when players were potentially showing signs of gambling-related harm.
Richard Watson, Gambling Commission Executive Director, said: "As a result of Casino 36’s failings, stolen money could have flowed unchecked through their casino and vulnerable customers were placed at risk of harm. This is simply not acceptable.
"Operators have to understand their customer base. This can only be achieved if they know their customers and ask the right questions to meet both their anti-money laundering and social responsibility obligations."