People who bet on World Cup matches with legitimate overseas bookmakers could face money-laundering charges.
Two days before kick-off in France, a grey area in the law has come under the legal spotlight.
Section 25 of the Organised and Serious Crimes Ordinance, dealing with laundering, includes a clause which refers to 'conduct which would constitute an indictable offence if it had occurred in Hong Kong'.
The clause is understood to have led some in the Department of Justice to believe that as bookmaking is illegal, once the proceeds of an overseas win arrive in the SAR they are 'dirty'.
Using them - putting them in a bank account, for instance - could therefore constitute money laundering.
But others argue Hong Kong law could not make money legitimately obtained in another country illegal when it arrives here.
Detectives believe the argument may only be settled by a test case.