At least two syndicates have been preying since 2015 on tourists gambling in casinos in the Philippines, with the police tallying 11 kidnap victims so far, including a Singaporean rescued on Tuesday.
"These two groups are composed mostly of Chinese nationals and Singaporean nationals. Singaporean nationals, but also of Chinese descent. They always target Chinese and Singaporean (gamblers)," national police chief Ronald de la Rosa told reporters yesterday.
On Tuesday, an anti-kidnapping unit rescued Singaporean Wu Yan, 48, from 14 men holding her captive in a room in a condominium in Paranaque City, an hour south of the capital Manila.
Investigations showed that Ms Wu was racking up heavy gambling losses at the Solaire Resort and Casino in Paranaque on Monday, when three men and a woman befriended her and lent her money.
When she kept losing, they offered to take her to another casino where she might get lucky. Instead, they took her to their safehouse at Bayview International Towers less than a kilometre away.
Two of the men were later identified as Malaysians Ng Yu Meng and Goh Kok Keong.
Ms Wu was beaten and forced to plead in a video to her family in Singapore to send US$180,000 (S$246,000) for her release.
She was rescued after a guard at the condominium chanced upon her as she was trying to escape, and notified the police.
A friend of hers in Singapore had also alerted the authorities in the Philippines.
It turned out that government agents were already at the building to investigate another kidnapping - involving a Hong Kong national who was also snatched from a casino a week earlier.
The police later arrested 43 suspects, who were all Chinese nationals except for the two Malaysians.
Mr de la Rosa said the police were searching for more suspects, including the ringleader, identified in a diagram briefly shown to reporters as "Chen Deqin".
He said the same syndicate that abducted Ms Wu was responsible for two more kidnappings. One was that of the Hong Kong national, who was taken on July 9 but managed to escape, and a Chinese who paid 300,000 yuan (S$60,700) after being kidnapped last month.
Senior Superintendent Glenn Dumlao, head of the police's Anti-Kidnapping Group, said these loan-shark and kidnapping syndicates usually scour casino floors for victims in teams of four.
They do not go for local players but tourists, who are more vulnerable to threats and intimidation.
They would pass off as players, and then as financiers, targeting those who were losing heavily, and then lending money to them.
In turn, they would charge a 10 per cent cut on the loan, and another 10 per cent on their target's winnings.
If the player was already deep in debt, they would tell him he could get lucky at another casino. They would offer him a ride, but take him instead to their safehouse, where he would be beaten and threatened.
Mr Dumlao said that in one video, the victim had a gun pointed at his head. He said all ransom payments had involved wire transfers from China to the Philippines.
Police chief de la Rosa, however, stressed that the police were "not against foreigners coming to the Philippines to gamble".
He said: "But we are anti-criminals. We are especially against foreigners who will come here to commit crime. We do not tolerate that."