Independent lawmaker Patrick Illidge was being questioned on allegations of bribery and money laundering, according to prosecutors. He came in voluntarily and was being held in pre-trial detention.
"He will now be interrogated until we run out of questions," Solicitor General Taco Stein said.
Last year, a publicized video showed Illidge seeming to accept stacks of money from the owner of the Bada Bing strip club in Simpson Bay. The video was sent anonymously to two newspapers.
Authorities later announced they were probing allegations that a former opposition leader asked strip club owner Jaap van den Heuvel to make the tape so he could blackmail Illidge to join his political faction and break the ruling coalition. Van den Heuvel was arrested last year.
Illidge's lawyer could not be reached for comment.
In St. Maarten's legal system, prosecutors don't file charges before a case is taken to court. Authorities wouldn't reveal specifics about their case against Illidge but said they have an order from the high court to prosecute.
"Unless we find that there is no evidence or a perfectly normal explanation, there will be prosecution," Stein said.