Crackdowns on illicit drug operations may have dealt a heavy blow to the narcotics business, but they have also provided an opportunity for unscrupulous law enforcers and their associates to exploit the campaign for their benefits.
Pol Capt Thirarat Suwannawat, 38, centre, a deputy police inspector at Bang Yi Khan police station, has been arrested for allegedly forming a gang that poses as narcotics suppression officers and robs drug suspects.
Posing as members of Narcotics Suppression Bureau (NSB) squads, active duty and former policemen have been robbing drug suspects and extorting money from them instead of bringing them to justice.
Their illegal activity was exposed after some of their victims lodged a complaint with the police, leading to the arrest of one of the gangs.
Police said the complaint was filed by Prachak Choksiri, 28, and his wife Samitanan Chayayothinkun, 25, residents of Ruam Thang Fan Sena Villa housing estate in Pathum Thani's Lam Luk Ka district, on Oct 8.
The couple filed a complaint with Khu Kot police, saying their house was raided by a group of men who claimed they were narcotics police. They demanded to search the place for drugs.
Police said the gang blindfolded and tied up the couple before searching their house and forcing them to reveal their ATM password.
They made off with 1.6 million baht in cash and other assets including a .22 pistol, four watches and an iPhone.
Pol Maj Gen Thawichat Phalasak, the investigation chief for Provincial Police Region 1, looked into the case himself after receiving the complaint and started hunting for the gang by checking the criminal records of robbers who had used similar methods.
His team eventually found a suspect identified as Sarawut Chuimuangsi, 44, who is wanted under an arrest warrant from the Provincial Police Region 2 for robbery.
A check of Mr Sarawut's phone records showed he had called Chuphong Sathongyot, 47, several times before the couple's house was robbed.
Investigators met Mr Chuphong in Phitsanulok and began questioning him to find out whether he was involved in the raid. Mr Chuphong eventually admitted to the wrongdoing, police said.
His account led to the arrest of three suspected gang members _ Ekkarat Chumchuea, 25, Aniwat Rodet, 25, and Pol Capt Thirarat Suwannawat, 38, deputy inspector at Bang Yi Khan police station in Bangkok.
"Pol Capt Thirarat is called nai [boss] by the others [in the gang]," deputy national police chief Ek Angsananon said. "He devised the raids and divided stolen assets among the members."
Pol Capt Thirarat used to be an officer of the NSB while Mr Sarawut, who is still at large, is his friend and was also once an informant for the officer, according to investigators.
Pol Capt Thirarat, whose previous name is Wirat Thongyu, was suspended from the force in 2010 after being accused of extortion. The court later dropped the charge and he resumed his work as an inspector at Thammasala police station in Bangkok before being transferred to work as Bang Yi Khan's deputy police inspector.
Mr Sarawut asked Pol Capt Thirarat to form a robbery gang because the officer had a great deal of knowledge about drug suspects, police said.
Information provided by the deputy inspector was used to choose targets whom they believed would keep their mouths shut after the robberies to avoid being arrested for drugs, Pol Maj Gen Thawichat said. The gang members later admitted they had posed as NSB policemen and robbed about 10 drug suspects in Pathum Thani, Nonthaburi and Chon Buri, police said.
Pol Capt Thirarat and his accomplices are among many gangs using similar tactics, police say.
On Sept 1, Thammasala police arrested a three-member gang, led by Pol Sr Sgt Maj Wiraphong Saemsimuang, 46, an officer of Sam Sen police station, on charges of detaining a drug suspect and extorting money from him.
There are at least another two gangs in areas under the jurisdiction of Provincial Police Region 1. Among their members are former police officers, said Pol Maj Gen Thawichat.
As for Pol Capt Thirarat, the officer has been dismissed from his job by city police chief Kamronwit Thoopkrachang.
"We will not keep bad policemen. They must be punished," he said.