Six police, including the wife of businessman and suspected crime boss Chaiyanat "Tuhao" Kornchayanant, have been sacked for alleged involvement in Chinese gangs and the drug trade.

They were sacked on Monday, while Mr Chaiyanat already faces an additional charge of money laundering, police said on Thursday.

Police said they enough evidence, including statements from more than 400 witnesses, to prove the suspects guilty of various charges, including taking bribes. There are 37 suspects in the case, 19 of whom have been arrested, and another 70 are either wanted or have been charged in a related drug case.

Among the six fired police are Mr Tuhao's wife, Pol Col Wanthanaree Kornchayanant, who was found to have been involved in Mr Chaiyanat's money laundering case. The other five allegedly demanded bribes.

They are a deputy commissioner of Provincial Police Region 6, a police driver, a deputy chief of Lat Phrao station's traffic police, and two investigators at Yannawa station.

Mr Chaiyanat's businesses relied on the use of hundreds of coaches, 33 of which are reportedly owned by a cousin of Prime Minister Prayut Chan-o-cha.

Police said the PM's relative operated a coach rental business and owned the coaches in 2019 before Mr Chaiyanat was found to be involved in the drugs trade.