The midfielder joined Manchester United last summer
Paul Pogba's transfer from Juventus to Manchester United is under investigation from FIFA.
The French international rejoined Manchester United last summer after spending four years in Serie A with Juventus. Pogba's transfer fee was over €100 million.
FIFA have written to the Old Trafford club "to seek clarification on the deal". The BBC report the "clarification" has to do with the amount of money Juventus received in the deal.
The newly published book Football Leaks: the Dirty Business of Football revealed that Pogba's agent Mino Raiola was paid €41 million for the deal.
Pogba's return to Old Trafford has been mixed so far, with the French star failing to live up to the heights he hit with Juventus in Serie A.
The French midfielder has scored seven goals in 48 appearances for the team this season. He has also won the League Cup with United and could still win the Europa League later this season.
While FIFA have not accused Manchester United of any wrongdoing, the seeking of "clarification" on the deal is unusual.