The administrators running Rangers have said they do not know the whereabouts of £24m which was lent to the club.
The money was lent to the club by Ticketus, a firm which hoped to profit from future season ticket sales.
David Whitehouse of Duff and Phelps said they did not have "visibility" of where the money had gone.
Meanwhile, former Rangers chairman Alastair Johnston has asked the Crown Office to investigate Craig Whyte's acquisition of the club.
He said: "I have today written to the Crown office asking for an investigation into the background surrounding the acquisition of Rangers Football Club by Craig Whyte, and in particular whether there is evidence of fraud."
A Strathclyde Police spokesman said: 'We can confirm that we have been passed information regarding the ongoing situation at Rangers Football Club. This is currently being examined. It would be inappropriate to comment further."
Speaking about the "invisible" £24m, administrator Mr Whitehouse said he believed the funds went through a parent company account rather than the account of the company now in administration.
He added that the administrators were checking with Rangers' former lawyers.
He said the Ticketus debt was not secured against the assets of the football club.
It means the ticket firm is unlikely to be repaid in full should Rangers exit the administration process.
Instead, Ticketus and other creditors would be asked to agree to a Company Voluntary Arrangement (CVA) to receive a percentage of what they are due.
Rangers FC Group, a separate entity from the club itself, remains solvent.
Ticketus loaned Rangers the money in return for flows of future season ticket sale revenue, a primary source of the Ibrox club's income.
David Whitehouse, from administrators Duff and Phelps told a press conference: "Our understanding is that the funds from Ticketus didn't come through the company's account, they went through a parent company account so we haven't got visibility on that.
"Ticketus don't have security on the assets of the club."
Ticketus have refused to comment on the Rangers season ticket deal, citing client confidentiality.
The Ibrox club entered administration on Tuesday after HM Revenue and Customs (HMRC) pursued legal action at the Court of Session in Edinburgh over alleged unpaid VAT and PAYE totalling about £9m.
Rangers are also awaiting the outcome of a tax tribunal over a disputed bill, plus penalties, totalling £49m.
Club chairman Craig Whyte, who assumed control of the club from Sir David Murray in May of last year, was reported on Monday as saying this potential liability to HMRC could reach up to £75m if the club lost the tribunal.
In a statement, Duff and Phelps' Paul Clark said the administrators "are hopeful that a CVA can be achieved and these are measures that are put in place and deal with all of the club's liabilities".
However, Mr Whitehouse said a CVA was not imminent, adding: "We don't know the quantum of HMRC debt yet because clearly the larger tax case hasn't been decided yet."
Mr Clark reiterated the administrators' belief that Rangers "will continue as a football club".
And he said: "We do not think that liquidation and the closure of the club is a likely outcome at all.
"We need to stabilise the financial position and ensure from now on income exceeds expenditure.
"We fully understand the 140 years history of Rangers football club and are taking steps to ensure this history will endure."
Earlier, the Rangers manager Ally McCoist and his players were told that an immediate review of staffing was under way.
Job losses seem almost certain but there will be no detail until next week at the earliest.
The administrators also confirmed that they were considering several expressions of interest in the club.