Police spokesman Ricardo Henson said the man was arrested before dawn Sunday but has not been charged yet.
Citing the territory’s privacy rules, Henson declined to give further details about the suspect, saying police will issue a statement “as soon as more information can be divulged.”
The bodies of Michael and Thelma King were found Friday in their condominium at the Ocean Club Resort on St. Maarten, a 16-square-mile territory with about 50,000 inhabitants that shares a small island with the French dependency of St. Martin.
Chief Prosecutor Hans Mos said both Americans appeared to have suffered fatal stab wounds. The woman was found tied to a chair, and the man was lying on the floor, partially over an overturned chair. Both were in their 50s.
Autopsies were expected to be conducted Monday, according to Mos. Relatives of the slain couple have arrived in the territory.
Friends say the Kings were part-time residents of St. Maarten and owned several homes, including a condominium in Mount Pleasant, S.C.
Terry Tamblyn, a resident of South Carolina’s coastal city of Isle of Palms, told The Post and Courier newspaper that King was a retired insurance executive who later started a successful printing business that he sold. He said King also owned a couple of restaurants on St. Maarten.
Local restaurant owner Topper Daboul has told The Associated Press that he and Michael King were building a rum factory together on the territory.
Daboul said he last saw King on Wednesday afternoon and “some other friends had drinks with them that night.” He said he wasn’t able to reach the Kings on the phone Thursday, so he drove to their house the next day and banged on the door. He said he asked a person on the premises to climb over a fence to see if anyone was in the house. Daboul said the person reported a lifeless man leaning over a chair inside the house.
Shortly after the slayings were announced, the St. Maarten government said “every government resource is being brought into play to investigate and solve this case.” Prime Minister Sarah Wescot-Williams said she was “shocked” by the murders.
Police said roughly 25 officers were part of the investigative team.