Six people - three immigration police, two Thai men and a Nigerian - have been arrested for colluding in forging visa stamps for foreigners entering the country illegally.
Arrest warrants were approved by the Criminal Court for Pol Snr Sgt Maj Witthayakorn Sarachan, 39; Pol Snr Sgt Maj Thepparit Yorsaeng, 47; Pol Cpl Supachai Seemasing, 31; Wichet Thaweekayuchan, 39; Somsak Bilrem, 44; and Nigerian national Adeola Victor Adefolarin, 34, Immigration Bureau chief Pol Lt Gen Surachate Hakparn said during a media briefing on Friday.
Their detention followed the earlier arrest of a Cameroon woman, Nta Mirelle Laure, 34, for illegal entry during recent raids targeting premises housing foreigners overstaying their visas.
She was found to have a fake visa stamp in her passport.
Police extended the investigation, leading to the arrest of the six suspects for forging visa stamps, the Immigration Bureau chief said.
The Nigerian acted as an agent, contacting foreigners who had illegally entered the country and wanted to stay here. He charged them 30,000-40,000 baht each for fake visa stamps.
The Nigerian forwarded lists of customers to Mr Wichet and Mr Somsak, who collected service fees from the agent and later contacted Pol Snr Sgt Maj Thepparit.
The officer then ordered the two other immigration officers, both based at Suvarnabhumi airport, Pol Snr Sgt Maj Witthayakorn and Pol Cpl Supachai, to handle the procedures.
Mr Wichet and Mr Somsak had come to know Pol Snr Sgt Maj Thapparit when they assisted police at the Sadao immigration checkpoint in Songkhla.
Pol Lt Gen Surachate said the bureau also arrested five other male foreigners – three from Nigeria and one each from South Africa and Ivory Coast – for having fake visa stamps in their passports. The five had worked at language schools.