Paul Gambaccini, who started working as a Radio 1 DJ in 1973, told Nicky Campbell on Radio 5 Live he became aware of the allegations against Savile in the 1980s, and had heard of them being discussed by a reporter at a wedding 10 years ago.
Campbell reminded Gambaccini that his "particularly lurid accusation" was not yet in the public domain, prompting the guest to question why.
Gambaccini went on to say: "The expression I came to associate with Savile's sexual partners was either one used by production assistants or one I made up to summarise their reports... 'under-age subnormals'.
"He targeted the institutionalised, the hospitalised - and this was known. Why did Jimmy go to hospitals? That's where the patients were."
Gambaccini described the late presenter as "a man who conned an entire society" at a time when paedophilia was "considered so far beyond the pale that people didn't believe it happened".
Savile's great niece Caroline Robinson revealed this week that the TV personality had sexually assaulted her when she was just 12 years old.
BBC director general George Entwistle told MPs today (October 23) that the corporation is investigating up to 10 "serious allegations" of sexual harassment involving past and present employees, and expressed his "grave regret" over the scandal.
His comments followed the broadcast of a Panorama documentary last night regarding an axed Newsnight investigation into Savile's behaviour.
Peter Rippon, editor of the latter programme, confirmed this week that he is "stepping aside" from the role following his decision to drop the report.
It was recently announced that the Metropolitan Police enquiry into alleged sexual abuse of children by Jimmy Savile and others has now become a formal criminal investigation.
