A new witness has come forward in the 2005 disappearance of American teenager Natalee Holloway, bringing a Dutch college student back into the spotlight as a prime suspect.

The Prosecutors' Office says the new witness claims the only suspect in the case, Joran van der Sloot, confessed to her that he was involved in dumping Holloway's body at sea.

But prosecutor Hans Mos said Tuesday that more evidence is needed to build a case against Dutch college student Van der Sloot.

Mos further told FOX News that wire reports about the new evidence were "much ado about nothing," since the new witness couldn't provide definitive evidence. And Mos noted that Van der Sloot already has given many different stories about what happened.

Click here for photos from the case.

Investigators reopened the case earlier this year based on similar admissions caught in hidden-camera recordings by a Dutch TV crime show. But in February, judges rejected an attempt to arrest Van der Sloot for a third time in Holloway's disappearance.

He had been released due to insufficient evidence the first two times he was arrested.

Aruban prosecutors had sought to detain him based on hidden-camera recordings in which Van der Sloot said Holloway collapsed on the beach after they left the bar. He then called a friend to dump her body at sea, according to the video shot by reporter Peter De Vries.

Van der Sloot's attorney, Joseph Tacopina, said in February that his client was not responsible for the Holloway's death and that the tapes did not amount to a confession.

"There was no confession, no admission of a crime by Joran on any of these tapes, which is very telling," Tacopina said on ABC's "Good Morning America."

Holloway, 18, of Mountain Brook, Alabama, was last seen in May 2005 leaving a bar with Van der Sloot on the final night of a high school graduation trip to the Dutch Caribbean island. She attended junior high in Clinton, Miss., and her father still lives in Meridian.

The Associated Press and FOXNews' Meredith Orban contributed to this report.