ORANJESTAD, Aruba - Prosecutors yesterday closed their investigation into the disappearance of American teenager Natalee Holloway, saying they still believe three young men were involved in her death but can't prove it after 932 days of searching failed to turn up a body.

The three main suspects in the case were re-arrested last month after prosecutors in Aruba discovered online chat sessions they hoped would break the case open. But none of the men talked in custody, and without the 18-year-old's body, prosecutors said they had no recourse but to close the most notorious missing persons case in the Caribbean.

If the three suspects were put on trial, the lack of evidence "would lead to an acquittal," the Public Prosecutor's Office said in a statement.

Moving Holloway into the cold-case files "is a tough burden to bear" for her parents, they acknowledged, but the prosecutors said they had little choice.

"The public prosecutor's office and the police have gone the extra mile and have exhausted all their powers and techniques in order to solve the mystery of the disappearance of the girl," the statement read.

Holloway disappeared on May 30, 2005, the last night of a trip with members of her Mountain Brook, Ala., high school graduating class. She was last seen leaving a bar with the three suspects: Joran van der Sloot and brothers Deepak and Satish Kalpoe, who all lived on this Dutch island off the coast of Venezuela.

Holloway's parents, who divorced years before her disappearance, have pushed hard to find what happened to their daughter - and Americans have followed every development.

Police, soldiers and hundreds of volunteers combed hillsides and beaches of this 75-square-mile island. Divers searched the sea bed offshore. Dutch F-16 jets equipped with search equipment conducted overflights. Dogs sniffed for a body.

Investigators interviewed hundreds of potential witnesses and arrested - and re-arrested - several suspects.

At times, it seemed Aruba itself was on trial, as some U.S. politicians and journalists assailed its ability to investigate the case.

Holloway's mother, Beth Twitty, is "terribly disappointed" with yesterday's decision, her spokeswoman said.

The prosecutors said they believe van der Sloot and the Kalpoe brothers were involved in Holloway's disappearance. An attorney for van der Sloot said it is unfair for them to say so without filing charges.

"Give this kid his due," attorney Joseph Tacopina said. "He's been incarcerated twice falsely. They've investigated up and down everything in his life."

Van der Sloot, who was re-arrested last month in the Netherlands where he attends college and held for several days, was in Aruba yesterday enjoying "a celebratory family event," Tacopina said. *