Prince Andrew has defended his former friendship with Jeffrey Epstein, saying "at no stage" did he "see or suspect" any criminal behaviour.
Epstein, 66, took his own life in a jail cell this month while awaiting trial on sex trafficking charges.
In a statement, the Duke of York said he wanted to "clarify the facts" around his "former association or friendship" with the United States financier.
He said it was a "mistake" to meet Epstein after he left prison in 2010.
"During the time I knew him, I saw him infrequently and probably no more than only once or twice a year," the 59-year-old prince said.
"I have stayed in a number of his residences. At no stage during the limited time I spent with him did I see, witness or suspect any behaviour of the sort that subsequently led to his arrest and conviction."
The duke - who said he first met Epstein in 1999 - added that he had "tremendous sympathy" for all those affected by Epstein's behaviour.
"His suicide has left many unanswered questions and I acknowledge and sympathise with everyone who has been affected and wants some form of closure."
Allegations against Epstein began to surface in 2005 when the parents of a 14-year-old girl told police in Florida he had molested their daughter at his Palm Beach home.
The financier was accused of paying underage girls to perform sex acts at his Manhattan and Florida mansions between 2002 and 2005.
A controversial secret plea deal saw him plead guilty to a lesser charge of soliciting a minor for prostitution. He received an 18-month prison sentence and was released on probation in 2010.
Prince Andrew was photographed with Epstein in New York's Central Park in late 2010 - after the tycoon was released from jail.
Footage has also emerged reportedly showing the prince at Epstein's mansion in Manhattan in 2010.
Prince expresses fresh regret over associating with Epstein
In the statement, released on Saturday, the duke added: "I have said previously that it was a mistake and an error to see him after his release in 2010 and I can only reiterate my regret that I was mistaken to think that what I thought I knew of him was evidently not the real person, given what we now know.
"This is a difficult time for everyone involved and I am at a loss to be able to understand or explain Mr Epstein's lifestyle.
"I deplore the exploitation of any human being and would not condone, participate in, or encourage any such behaviour."
In July 2019 Epstein was charged in New York with further allegations of sex trafficking and conspiracy and was due to face trial next year.
He pleaded not guilty to all the charges but if convicted, was facing up to 45 years in prison.
The Queen's third child quit his role as a UK trade envoy in 2011 after the fallout from the photos of him and Epstein in 2010.
The duke had been appointed the UK's special representative for international trade and investment in 2001 after retiring from the Royal Navy.
BBC royal correspondent Nicholas Witchell said Saturday's statement was a response to speculation in the media following the publication of footage of the duke at Epstein's house in New York.
"I think that this is a consequence of the build-up of press exposure in the days since and, as he would see it, a need to get his story, his rebuttal, out in as forceful terms as he can," he said.