Steve Gregory Croes, whom authorities earlier identified only by his initials, "S.G.C.," said he was contacted by police Thursday night and went to the station voluntarily to give a statement, according to the employer, Marcus Wiggins. Croes was arrested early Friday.
Croes also said he knew one of two Surinamese brothers being detained in the case because he went to the same Internet cafe, Wiggins said.
Croes was working as a disc jockey on the "Tattoo," a large tourist boat offering nightly dining, dancing and swimming, Wiggins said.
Wiggins said he had seen neither the Surinamese brothers, Deepak Kalpoe, 21, or Satish Kalpoe, 18, nor fellow detainee Joran van der Sloot, 17, the son of a justice official from Holland, aboard the boat. A brochure for the boat says patrons must be 18 or older.
"I've never had problems with him," Wiggins said of Croes. "He keeps to himself and shows up to work every day and does his job."
Wiggins said Croes had worked for the boat "for a period of time," but he could not say how long exactly.
Natalee's mother, Beth Holloway Twitty, told the Associated Press. "Whether or not he's involved with my daughter's disappearance, I can't wait to find out that answer."
Prosecutors have gone back to court to ask that van der Sloot and the Kalpoe brothers stay in jail. Under the law, a judge must review their case after 10 days and decide their status.
"The process allows for a period of time for the prosecutor to do the investigation. That can go well over 100 days," said local attorney Lincoln Gomez.
A judge was expected to rule as well Friday on another petition, from van der Sloot's father, Paul van der Sloot, to be able to visit his son in jail. None of the four detainees has been formally charged with a crime.
Authorities' announcement of Croe's arrest Friday came nearly three weeks after Holloway's disappearance in the early morning hours of May 30, the same day she was to return from a five-day trip with 124 other students celebrating their high graduation in Mountain Brook, Alabama.