The Scottish Football Association have confirmed they will investigate claims made by former Rangers director Hugh Adam that payments made to players were not disclosed to the governing body.
Adam claimed in a newspaper interview that some payments had been excluded from contracts lodged with the SFA.
The SFA are already conducting an independent enquiry into the activities of Rangers and whether there have been any potential breaches of their articles of association.
The accusations are the latest blow for the Glasgow club who are currently in administration.
Adam was involved with the club until 2002, when his 30-year association with the club came to an end and says the payments could have started as early as the mid-1990s.
"They weren't included in the contracts," he told the Daily Mail.
"They definitely weren't.
"That was the whole point of them. If they'd been included in the contracts, they would have had to have paid tax on them.
"I don't think a lot of the other directors knew an awful lot about it. David Murrary (the former owner of the club) kept everything to himself.
"When I was on the board, I knew all about them. I just didn't know the details of them. They became accepted."
In a statement SFA chief executive Stewart Regan said: "We are aware of the most recent allegations made against Rangers FC by a former director of the club.
"We shall investigate this matter thoroughly before making any further comment."