regrets: Sir David said selling Rangers to Craig Whyte, below, had 'tarnished the legacy' of his 23 years as owner.
The millionaire businessman has broken his silence on the sale of the club to Whyte last May and apologised to fans for deciding to do a deal with the venture capitalist.
Sir David conceded Whyte's subsequent running of the club, which took Rangers into administration on February 14, has "tarnished the legacy" of his 23 years as owner.
He was unable to explain how Whyte had managed to secure a £24.4 million advance from London-based finance company Ticketus – raised against future season ticket sales – before he had taken ownership of the club, and insisted he had no knowledge whatsoever of that plan.
The sale of the club is being investigated by police, and there could be serious implications for Whyte and lawyer Gary Withey of London legal firm Collyer Bristow if any wrongdoing is discovered.
Mr Withey, who was also made Rangers' company secretary, has now left Collyer Bristow and is no longer involved with the club.
When asked why he had sold to Whyte, Sir David said: "I was primarily duped. My advisers were duped, the bank was duped, the shareholders were duped. We've all been duped. Is duped the right word? Duped is the right word.
"It does not look good for Craig Whyte. I deeply, deeply regret selling the club to Craig Whyte. And if the information had been available to me at the time I wouldn't have done it. I did it in good faith.
"And I can only apologise. I wish I'd never done the deal with Craig Whyte."
Rangers enjoyed a period of unprecedented success during Sir David's ownership but his stewardship of the club, which saw it at one point run up debts of £80m and saw it still owing £18m to the bank when it was sold, has been questioned by fans in the light of Whyte's disastrous reign.
Murray Group finance director Mike McGill sat alongside Sir David as he answered questions on the sale of Rangers and its plunge into administration.
When asked if there was any legal recourse against Whyte or Collyer Bristow under the terms of the Share Purchase Agreement (SPA) which spelled out to shareholders details of the club's sale, Mr McGill said: "He (Whyte) did not follow the terms of the SPA –he put money into the club through a route other than that which we had set out."
Whyte retains an 85.3% shareholding in the club and will have to give that up in order for Rangers to come out of a Creditors Voluntary Agreement (CVA).
Sir David says the shares "might be worthless", but he hopes one of the several parties interested in buying the club can indeed complete a CVA, which would save the club from liquidation.
Sir David said: "A CVA would be preferable. Of course it would. Coming back as a 'newco'? That's not in the best interests of the game in this country. And it's not in the best interests of Rangers." The former owner also hit back at claims by former director Hugh Adam that Rangers had made illegal payments to players in the 1990s.
He rubbished suggestions that players in the controversial Employee Benefit Trust (EBT) scheme the club used between 2001 and 2010 were given two contracts.
The allegations by 86-year-old Mr Adam prompted an SPL investigation, as it is against registration rules for players to have two contracts for playing activities.
Sir David also cleared former Rangers secretary and current SFA president Campbell Ogilvie of any involvement in the EBT schemes.
And he spoke of his "deep regret" that Rangers manager Ally McCoist has been left alone at the helm of a "rudderless ship" in his first year in management.