BBC Scotland has uncovered new evidence showing Rangers administrators Duff and Phelps knew Craig Whyte had sold season tickets to buy the club.
The recording of a conversation indicates they were intent on denying it because they thought they could get away with it.
A Duff and Phelps spokesman said the words were taken "out of context".
The BBC reported Duff and Phelps partner David Grier may have known about the Ticketus deal last April.
This was before Mr Whyte's takeover.
Mr Grier denied any knowledge of the deal until August 2011.
The BBC has obtained a recording of a meeting between Mr Whyte and Mr Grier, which show Duff and Phelps did know.
Mr Whyte bought Rangers from Sir David Murray for £1 and paid an £18m debt to Lloyds Bank by selling three years of season tickets to finance firm Ticketus for £25m.
As well as being involved in Mr Whyte's takeover, Duff and Phelps were appointed as Rangers' administrators after the club plunged into insolvency in February 2012.
In May, a BBC Scotland investigation suggested that Mr Grier may have known that about the controversial Ticketus deal before the Whyte takeover was complete.
Mr Grier, and Duff and Phelps, denied the claims and said he was unaware of this particular Ticketus deal until August 2011.
Last week, in a BBC interview, Mr Whyte said that "everybody who was involved in the deal team at the time knew about" the Ticketus deal.
He added: "They (Duff and Phelps) knew everything, they attended meetings, they were copied into all the emails, they were there on the day of completion. They knew from the start."
BBC Scotland has now received a secret recording that Mr Whyte says he made at a meeting between him and Mr Grier in a private members' club in London on 31 May, after its investigation was broadcast.
The recording, which is to be used in a forthcoming court case involving Duff and Phelps and Mr Whyte's former lawyers Collyer Bristow, has been obtained legitimately by BBC Scotland.
During the exchange Mr Grier and Mr Whyte discuss Ticketus and Saffreys, one of the companies of lawyers involved in the transaction. Saffreys were acting for Mr Whyte with responsibility for dealing with Ticketus.
Mr Grier said: "I'll tell you what we're doing with that just so you…"
Mr Whyte: "Yeah."
Mr Grier: "We, we went to see counsel yesterday and had a full sort of debrief of all the email correspondence."
Mr Whyte: "Yep."
Mr Grier: "Now, the fact is that we probably did know what was going on with Ticketus. There's no email traffic whatsoever."
Mr Whyte: "That says that you did?"
Mr Grier: "That says that we did."
Mr Whyte: "But we all know that you did and f****** hell."
Mr Grier: "Yeah, yeah. There's no…we were not involved in dealing with Ticketus directly."
Mr Whyte: "Yeah. So you knew the structures of the deal. You were dealing with Lloyds."
Mr Grier: "Absolutely."
Mr Whyte: "And the Ticketus part was Saffreys."
Mr Grier "Yeah. So we've maintained that line quite rigorously."
BBC Scotland has been able to confirm with a voice recognition expert that the recording is of Mr Grier.
Duff and Phelps spokesman Marty Dauer said: "As we have previously stated, Duff and Phelps maintains that our conduct of the Rangers administration was carried out to the highest professional standards.
"We do not respond to information that is taken out of context, as we believe is the case in the BBC story.
"We welcome the opportunity to review a complete copy of the information that the BBC references in its story."