( CNN ) -- A Dutch man once considered a suspect in the 2005 disappearance of Alabama teenager Natalee Holloway has told a television station he dumped her body in a swamp , Aruba 's chief prosecutor told CNN . However , Joran van der Sloot 's claims to Dutch station RTL-5 are `` unbelievable , '' prosecutor Peter Blanken said . RTL-5 said Tuesday it had `` acquired exclusive material containing a statement by Joran van der Sloot '' regarding Holloway 's disappearance . `` This material was first offered to us in 2009 , '' Remko van Westerloo , the station 's director of programming , said in a statement . `` Obviously , our initial response was skeptical , '' van Westerloo said . `` However , we did feel that this interview required thorough research . We 've spoken to a variety of experts and several critics . These findings resulted in a TV special which will air this Sunday . It 's up to the viewers to form their own opinions on the matter . '' The statement did not divulge the contents of van der Sloot 's interview . However , Blanken told CNN on Tuesday that van der Sloot says in the interview that he dumped Holloway 's body `` in a swamp on the north end of the island . '' `` He was very unspecific , '' Blanken said . Blanken said RTL contacted him about the interview last summer , and the station showed the interview to him to get his reaction . He said his office and Aruban police investigated . `` We tried to verify it , '' Blanken said . `` It could n't be true . We talked with several witnesses and reviewed several facts . The story is unbelievable and not true , in my opinion . '' He said his office told van der Sloot `` we 'd like him to come in and speak with us about it . He failed to respond . '' Asked why van der Sloot gave the interview , Blanken said , `` You should ask him . Maybe he wanted to be on camera or make some money . '' Holloway was 18 when last seen in the early hours of May 30 , 2005 , leaving an Oranjestad , Aruba , nightclub with van der Sloot and two other men , brothers Deepak and Satish Kalpoe . She was visiting Aruba with about 100 classmates celebrating their graduation from Mountain Brook High School in suburban Birmingham , Alabama . Holloway failed to show up for her flight home the following day , and her packed bags were found in her hotel room . Van der Sloot and the Kalpoes were arrested and released in 2005 in connection with the case . In 2007 , they were arrested a second time after Aruba 's then-chief prosecutor , Hans Mos , said he had received new evidence in the case . Van der Sloot , who was attending college in the Netherlands , was brought back to Aruba . But judges ruled the new evidence -- which included an Internet chat the same day Holloway disappeared with one of the three youths saying she was dead -- was not enough to keep them jailed . In 2008 , prosecutors sought unsuccessfully to arrest van der Sloot a third time after a videotape surfaced on Dutch television . In it , van der Sloot tells a man he considered to be his friend that he had sex with Holloway on the beach after leaving the nightclub , then she `` started shaking '' and lost consciousness . He said he panicked when he could not resuscitate her and called a friend who had a boat . The two put Holloway 's body in the boat , he said , and then he went home . The friend told him the next day that he had carried the body out and dumped it in the ocean . `` I did n't lose a minute of sleep over it , '' van der Sloot said on the tape . Holloway 's mother , Beth Twitty , told ABC at the time that the video showed van der Sloot was `` not innocent . '' But an Aruba court ruled there was not enough evidence to re-arrest him . Aruban prosecutors said authorities had met with van der Sloot in the Netherlands , but in a two-hour interview he denied any role in Holloway 's disappearance . Van der Sloot acknowledged to a Dutch television program he made the comments , but said he was lying . `` That is what he wanted to hear , so I told him what he wanted to hear , '' he said . `` When [ van der Sloot ] really wants to tell the truth , [ we hope ] he will , '' said Blanken , who took over as chief prosecutor in September . `` He did n't tell the truth [ this time ] . '' CNN 's Susan Candiotti contributed to this report .
Ex-suspect tells TV station he dumped Alabama teen 's body in swamp , Aruba prosecutor says . But Joran van der Sloot 's alleged confession `` unbelievable , '' prosecutor says . Alabama teenager disappeared on trip to Aruba in May 2005 . Nancy Grace has the latest breaking developments at 8 and 10 p.m . ET Tuesday on HLN .