Three Vietnamese gamblers were briefly detained at a Prey Veng casino after they allegedly gave illicit substances to fighting cocks in an unorthodox bid to improve their winnings in the ring.

Casino workers were in a flap after noticing the trio’s trickery on Tuesday in Peam Chor district, and ordered them to be detained by the casino security guard, according to Koh Roka commune police chief An Lov.

But rather than feeding the cocks steroids to give them a fighting chance, it appears the gamblers instead tried to weaken their own birds and throw the match.

“They cut the roosters’ skin and placed the medicine into it and when the roosters were ready to fight, they squeezed the place [where the incision was made],” Lov said, adding the rooster would then flee after just one spur.

“Then they bet on the other side because they knew they had used tricks . . . Sometimes they bet with 20 or 30 million dong [$880 or $1,320],” he said.

Lov said the three had been released by the casino security guard and confessed they had been hired by a third party to carry out the scheme.

The National Police website reported the incident, adding that “the casino ran without permission”. However, spokesman Kirth Chantharith could not be reached for clarification yesterday.

Another commune police officer, who declined to be named, said the Vietnamese-run casino was unlikely to be punished as he did not know if it was licensed.