The Austrian side is still owed over £1million from the £4m deal which took Jelavic to Glasgow in the summer of 2010, but are set to receive only a fraction of that amount after the Gers were placed into liquidation when the CVA offer to creditors was rejected.

Rangers could now be hauled in front of Fifa's Dispute Resolution Chamber in Zurich as Rapid step up the chase to recoup their cash.

Rangers will receive the full £5.5m fee from the sale of Jelavic to Everton in January and Rapid are determined to get their hands on money due.

Peter Klinglmuller, Vienna's head of communication, said: "It seems unfair to us we might not receive the money we are owed for the player when Rangers expect Everton to pay the fee they agreed for him.

"I don't know how the law works in Scotland but we're used to paying our transfer fees in full."

Fifa have confirmed an investigation into the matter is already underway, giving Gers chief executive Charles Green another major headache as he attempts to sort out an ever-growing mess at Ibrox.

Meanwhile, Sone Aluko is a target for MLS duo Houston Dynamo and New England Revolution after informing Gers he does not wish to transfer his contract to the newco.