Police on Friday said they had taken down an online gambling operation which raked in tens of millions of dollars, arresting 22 people.

Two of the suspects have been charged.

Superintendent Wilson Tam said a free game available in two major app stores was used to entice people to gamble.

Players were told they could exchange the points they accrued for money to be used for unauthorised gambling on mahjong and poker games, Tam said.

Officers said they also seized HK$6 million in cash and found computer records which showed gamblers had handed over HK$77.5 million since July 2019.

The police also said more than 50 bank accounts had been used to launder HK$240 million in crime proceeds.