Pak Kred police were informed by an exhibitor at the fair that a couple, who appeared to be Chinese nationals, had switched a fake diamond for a genuine six-karat diamond worth around B10 million on the first day of the fair.
Manthana Viyakaew, a sales assistant at M Tarun Co, said the two foreigners, a man and a woman, inquired about the price of the diamond on display and asked to look at it around 11:30am on yesterday.
After a brief discussion, the two returned the diamond and left. Ms Manthana examined the gemstone they returned and realised it was a fake and immediately contacted the fair organiser for assistance.
A review of security camera footage showed the couple left the fair by taxi. Police contacted immigration officials to watch for the duo, sending them images from the video footage.
Immigration police later detained a Chinese couple whose appearance matched the video images. They denied stealing the diamond and said they were just tourists visiting Thailand and about to return home. Police did not find the stolen diamond with them.
The sales assistant was asked if she could identify them and confirmed they were the couple who asked to the see the real diamond.
Pol Col Withit Chaniam, deputy superintendent of Pak Kred police station, said police would use witness accounts and images to support a request to the court for arrest warrants for the two detained Chinese nationals, and hold them pending further investigation.
He said they were believed be part of a seven-member Chinese gang. Police had been able to arrest another two suspects in Sa Kaeo province, and two more at a hotel in Yaowarat area. One had already left the country.
The police investigation was continuing.
Read original story here.