Cambodian authorities have detained four Chinese nationals accused of a kidnapping and extortion plot involving gamblers who’d rung up debts at a local casino.

On Monday, Cambodia Daily reported that National Military Police had arrested Ding Chunyaun, the owner of an unidentified casino in Poipet City, along with three accomplices for the kidnapping of three Chinese gamblers who’d run up a $1.22m debt at the casino.

One of the gamblers, identified as 51-year-old Chinese businessman Zhun Xiao Liang, owed the casino $770k, while the two other gamblers owed $300k and $150k. When they proved unable to honor their debts, Chunyuan ordered his accomplices to kidnap the trio in January.

Police said Chunyuan and his “mafia group” illegally detained the three gamblers in an apartment near the casino. Liang’s wife was reportedly sent mobile phone messages, including pictures of her husband, along with demands that she send money to make good on Liang’s gambling debts. Police didn’t specify whether Liang’s wife complied with the kidnappers’ demands.