Six policemen at Huai Khwang station face the charges of taking bribes in connection with alleged extortion of a Taiwanese actress's group at a checkpoint on Jan 4.

The charges carry a maximum sentence of life imprisonment and a fine of up to 400,000 baht.

Another senior sergeant major who was assigned to the same checkpoint was not charged because he was responding to another incident at the time.

Earlier the officers were charged with dereliction of duty for failing to take legal action against the group's illegal possession of vapourisers.

The bribery charges came after a Singaporean man told reporters on Wednesday that he paid 27,000 baht to the officers for the freedom of his group, which included Taiwanese actress Charlene An, from the checkpoint where police found his vaping devices.

The 33-year-old actress on Thursday posted a video clip to thank whistleblower and former politician Chuvit Kamolvisit for supporting her.

Mr Chuvit held a press conference at his hotel on Wednesday for the 29-year-old Singaporean man who identified himself only as "Sky" to speak about the incident at the police checkpoint in Huai Khwang district.