
The rubies and emeralds were stolen on Saturday at the Bangkok Gems and Jewellery Fair at Muang Thong Thani's exhibition complex in what Bangkok police say was the largest jewel heist in recent memory.
Named as Raul Armando Carranza, 32, Oscar Alexis Martinez Aguirre, 39, and Jaime Ballesteros Castaneda, 53, the three suspects were arrested in Chon Buri and are in Pattaya police custody.
The senior investigator in charge of the case, Pol Lt-General Chalong Sonjai, said CCTV footage proved that two more suspects, now thought to be on the run, operated as part of the gang. Chalong said one of the three men in custody is suspected of having stolen jewellery at the same fair last year. He said police suspected the jewels were still in Thailand.
Police are trying to determine whether Aguirre was the same person who recently snatched valuables in Bangkok's Pathum Wan police jurisdiction.
Police say the five suspects planned the theft in their home country and were based in Pattaya both before and after the heist. They travelled between Bangkok and Pattaya in a rental car.
Meanwhile, police have arrested three Malaysian men for buying electronic goods at Pantip Plaza's Nonthaburi branch, allegedly with fake credit cards.
The three suspects are Ui Kim Chew and Chen Wei Hua, both 28, and Lai Chin Ting 43. Police say they found two fake passports and 10 other fake credit cards in their possession, apart from the one used in the purchase. The three pleaded not guilty and are now in custody of Muang Nonthaburi police.