The circumstances of Kilmarnock's signing of Nigerian internationalist Reuben Gabriel may be investigated by FIFA after claims made by an agent in the player's homeland that he is owed money from the deal.

Emmanuel Babayaro, brother of former Chelsea defender Celestine, believes he should be remunerated as a result of clauses agreed when he sold Gabriel to Kano Pillars.

The midfielder left the Nigerian side to move to Rugby Park on a three-year contract last month but has yet to play a match. The move has now attracted fresh intrigue, with Babayaro intent on recouping a fee despite intimations that Kano had sold Gabriel's rights to another agent in a move which would negate any previous clauses.

"We have written to Kilmarnock," said Babayaro. "[Kano] promised to pay, but they have gone back on that. If my money is not paid, my lawyers will swing into action and I won't hesitate to sue all parties involved and bring the matter to FIFA."