A joint South Korean-Chinese fraud ring that swindled of 12.2 billion won ($8.73 million) from more than 80 victims in a romance scam has been caught, police said Tuesday.

The Busan Metropolitan Police arrested 12 suspects, including a Korean leader in his 20s and a Chinese leader in his 30s, on charges including conspiracy to defraud. Eight additional suspects were charged without detention.

According to police, the group recruited South Korean accomplices in their 20s and 30s and flew them to Cambodia and Laos, where they were trained in romance scam tactics. Impersonating overseas Korean women, the scammers approached male victims through social media and struck up online romances. Once the relationship developed, the scammers coerced the victims to invest in cryptocurrencies or gold futures.

Victims were then directed to bogus websites and invested amounts ranging from 1 million won to 2 billion won. If suspicions arose, the scammers would say things like “Don’t you trust me,” and tried to leverage their relationship to alleviate doubts.

When victims demanded their money back, the scammers would request additional deposits for fees or taxes and then disappear with the money.

From January to August, the fraudsters raked in 12.2 billion won from victims, spending the proceeds lavishly on hotels and entertainment venues overseas.

Police said there were 84 confirmed victims, mostly men ranging in age from their 20s to 70s.

The fraud ring operated with a hierarchical structure that rewarded or punished members based on their scam earnings, authorities said.

Police began investigating the case in April after receiving a tip from a victim.