The release of disc jockey Steve Gregory Croes came a day after a judge freed the father of a 17-year-old suspect in the disappearance of Natalee Holloway.
A judge ruled over the weekend that there was not enough evidence to hold Croes, 26, and Paul van der Sloot, 52, a high-ranking judicial official on the island whose son, Joran, was among the last people seen with 18-year-old Natalee the night before she was to return home to Alabama from a school trip.
Croes is a disc jockey on the party boat Tattoo, which offers nightly dining, dancing and swimming and docks near the Holiday Inn hotel where Holloway had been staying on Aruba, a Dutch protectorate.
Croes did not speak with reporters as he left the courthouse in the capital, Oranjestad, through a back exit.
Still jailed are the young van der Sloot and his friends, Surinamese brothers Deepak Kalpoe, 21, and Satish Kalpoe, 18. No one has been charged.
CBS News Correspondent Steve Futterman reports that after the three suspects are held for another eight days, authorities can make a request to the judge to hold them for an additional 60 days.
Under Dutch law, a suspect can be held for up to 116 days without charge if a judge decides police have good reason.
Searches for Holloway have been fruitless.
Joran van der Sloot appears to be the focus of the investigation, reports Futterman. He reportedly was alone with Holloway just before she vanished.
The three young men who remain jailed initially told police that after a night of eating, drinking and dancing, they took Holloway to a northern beach before dropping her off at her hotel around 2 a.m.
On Saturday, Satish Kalpoe's lawyer said his client admitted that his story was a lie.