Celtic chief executive Peter Lawwell is adamant his club have no case to answer over their use of an Employee Benefit Trust (EBT).
Celtic admitted using the tax scheme in one instance for former midfielder Juninho, but the Scottish Premier League have stated there was no question of them breaching their rules over the matter.
The SPL launched an inquiry into alleged undisclosed payments to players by Rangers, a probe that centres on the Ibrox club's use of EBTs from 2000 to 2011, before they were consigned to liquidation. An independent commission will hold a hearing into the allegations in November.
Rangers newco chief executive Charles Green last week pointed out that other clubs had used EBTs as he hit out at the SPL probe, but Lawwell is sure his club did no wrong.
He told several national newspapers: "It's absolutely straightforward. We know we operated one single EBT. HMRC know how we operated that EBT. The football authorities know how we operated that. We've no case to answer.
"I don't know how Rangers operated their EBT. HMRC know. The football authorities know and there appears to be a tribunal and a commission set up so it's straightforward. In some quarters people have tried to drag us into the debate and it's nothing to do with us. It's a red herring."
Lawwell defended his own role in Scottish football's summer of upheaval that followed the failure to prevent Rangers heading towards liquidation.
Lawwell is on the Scottish Football Association's professional game board and was also central to the renegotiating of the SPL's television contracts.
But he brushed off accusations by some Rangers fans that he had an undue influence.
"There is a whiff of paranoia around somewhere," he said. "I don't have an undue or inappropriate influence on Scottish football. There is nothing covert in terms of what is happening."
- Peter Lawwell
- Scottish Premier League