Authorities earlier pressed the same charges against Prasert Prommi, who is alleged to be the advisor to the city councillor for Bang Rak district and council chairman.
Crime Suppression Division deputy chief Pol Col Prasobchoke Prommoon said Lt Col Burin Thongpraphai of the Judge Advocate-General's Department requested Tuesday that charges be filed against the 54-year-old councillor after determining that the accusations were credible.
Mr Pipat denied all the charges, again insisting he has been falsely accused in retaliation for trying to remove illegal street traders from the city's footpaths. He vowed to prove his innocence in court.
Mr Pipat and Mr Prasert were taken into custody under martial law Aug 14 and will be held by the Criminal Suppression Division until at least Thursday. At that point, police will take both men to the Southern Bangkok Criminal Court to seek permission to detain him longer, pending an investigation.
The court will consider any requests for bail, said Pol Col Prasobchoke Prommoon.
Allegations were filed by street vendors near Wat Hua Lamphong and the Sam Yan MRT station. They alleged Mr Pipat and Mr Prasert were extorting money from vendors in the areas. Vendors alleged they weren't the only ones: On Aug 15, a Bang Rak thetsakit inspector was arrested for allegedly demanding similar payments from motorcycle taxi drivers.
Some other district councillors are believed to have made the extortion allegations to police. A City Hall source said many motorcycle taxi drivers and street vendors long have been paying protection fees to influential figures in their areas.