The man, whose face was not shown but who spoke with an American accent, said he had met Spacey at a summer theater and that the actor had eventually invited him to spend a weekend with him at his home in NY.
Exactly how Hollywood organizations will react to the allegations against Spacey remains unclear.
And they had also originally denied that the sordid allegations made against Kevin Spacey are the reason, claiming that it was a decision made "months ago".
Although Montana, who was in his thirties at the time of the alleged incident, never saw Spacey again, the memory has lived on.
Daniel told The Sun: 'Before I had a chance to do anything he got his d**k out.
Spacey said if he had behaved in the way Rapp describes then he owes him "the sincerest apology" and that he was "sorry for the feelings [Rapp] describes having carried with him all these years".
Montana said Spacey groped him in 2003.
An actor who worked with Kevin Spacey at the Old Vic theatre has said "a whole lot more" accusations will surface in coming days.
Responding to the allegations made by Rapp, Spacey - who won Oscars for The Usual Suspects and American Beauty - said he was "beyond horrified" but did not remember the encounter.
Spacey is also being heavily criticised for his weird attempt to blame the fact that he was drunk for the sordid "sexual advance" on such a young boy.
Spacey has been accused of sexual misconduct towards Star Trek actor Anthony Rapp when he was 14. "But I don't, like, squirm away initially, because I'm like, 'What's going on?' And then he lays down on top of me", he told BuzzFeed. He wrote that he's had romantic relationships with both men and women in the past but is now living "as a gay man" and wanted to be honest so he could examine "my own behavior". There was no reply to a request for comment from representatives for Spacey.
Netflix revealed yesterday that the decision to end the show after six seasons was made months in advance of the allegations against Spacey.
However, a report published Wednesday in the Guardian claims that "a number of people" have contacted the publication with stories about misbehavior by Spacey during his time as artistic director at the Old Vic.
Ridley Scott's "All the Money in the World", in which Spacey portrays oil tycoon J. Paul Getty, is still scheduled to premiere November 16 at the AFI Fest and hit theaters in December.
"I came forward with my story, standing on the shoulders of the many courageous women and men who have been speaking out to shine a light and hopefully make a difference, as they have done for me", he wrote on Twitter.