Former Rangers owner Craig Whyte has threatened legal action against the Ibrox club.
Whyte, who bought the club from Sir David Murray for £1 in May 2011, is taking action after an investigation found no evidence that he had invested in the current set-up.
The probe was commissioned by the Rangers board as Whyte was ineligible to play any role in a Scottish club after being banned for life in April 2012 for his part in their financial meltdown.
Law firm Pinsent Masons investigated claims made by Whyte of his involvement in the Charles Green-led consortium's acquisition of Rangers' business and assets for £5.5m last summer.
Green, who has since resigned from his role as chief executive of the third division champions, has denied the allegations.
In a statement to the London Stock Exchange, Rangers said: "Based on the assessment of the available evidence, the company considers the investigation found no evidence that Craig Whyte had any involvement with Sevco Scotland Limited (now called The Rangers Football Club Limited), the company which ultimately acquired the business and assets of The Rangers Football Club PLC from its administrators.
"Nor which would suggest that Craig Whyte invested in The Rangers Football Club Limited or Rangers International Football Club plc, either directly or indirectly through any third party companies or vehicles.
"On 28 May 2013, a letter before claim was sent to (inter alia) The Rangers Football Club Limited and Rangers International Football Club plc on behalf of Craig Whyte, Aidan Earley and (purportedly) Sevco 5088 Limited.
"The Rangers Football Club Limited and Rangers International Football Club plc will be preparing a robust response to the letter before claim.
"However, given that legal proceedings are threatened in the letter before claim, it would not be appropriate to make public any further content from the report or to comment further about the contents.
"Pinsent Masons' and Roy Martin's reports to the Company are confidential and legally privileged.
"This announcement is not intended to and does not serve to waive privilege in the contents of the reports which remain confidential and legally privileged."