Police from Macau, Hong Kong and mainland China are stepping up enforcement action against illegal World Cup betting as police from both Special Administrative Regions and from Guangdong province have launched a month-long crackdown on illegal football gambling, Hong Kong Standard newspaper reports.

The 2014 FIFA World Cup in Brazil kicks off on June 12 with the final set for July 13. In June 2010, Macau’s casino revenue declined 20 percent from the previous month, a drop that was attributed by some financial analysts to the World Cup keeping some gamblers away from gaming tables and slot machines.

Gambling revenue for the casinos fell to MOP13.6 billion (US$1.7 billion) in June 2010 from MOP17.1 billion in May. It went up to MOP16.3 billion in July. Deutsche Bank analyst Karen Tang wrote in July 2010 that Macau’s gambling industry would continue to be hurt by “temporary softness in VIP gaming as the World Cup approaches its final stages”. The illegal World Cup betting doesn’t help.

“We expect market growth to resume sequentially in August, which is traditionally the summer travel season,” she wrote in a note to clients at the time. Illegal betting on World Cup matches usually surges across Asia during the tournament.

The rewards of increased betting volume are attractive to the organizers, even though the risk of arrest is typically heightened.