In an interview with the US news channel, he claimed he repeatedly met the man in a casino. The Venezuelan offered him 10,000 US dollars.
Joran van der Sloot told how he watched Natalee, who was drunk, being hauled on board a vessel chartered by the Venezuelan. There was no struggle or anything, he said.
Natalee vanished on the Caribbean island of Aruba - part of the Kingdom of the Netherlands - on 30 May 2005. Joran van der Sloot has been arrested twice in connection with her disappearance, but without conclusive evidence he has never been brought to trial.
He now lives in Thailand, where he has come under suspicion of being involved in sex trafficking.
Joran van der Sloot said in the interview that he was helped by the two brothers Deepak and Sateesh who were briefly detained by Aruba police when Ms Holloway had gone missing.
The interview was cut short when Joran van der Sloot was asked about his father's involvement in the affair. According to earlier statements by Joran, his father, working for the Aruban Justice ministry at the time, bribed two policemen to remain silent about what they knew about the affair.
Joran's father and police on Aruba are refusing to comment.
Some time after the recorded interview was broadcast, Joran van der Sloot contacted Fox News and told them he had lied to the interviewer, Greta van Susteren.
Fox News is a commercial cable TV station in the United States.
The station is often accused of not living up to its trademarked slogan of "Fair & Balanced".
Fox News denies allegations that it paid Joran van der Sloot for the interview.
Fox was launched in 1996 by Rupert Murdoch's media conglomerate.