Fifa are investigating reports of unusual betting patterns on an international friendly this week.
Wednesday's game between Nigeria and Argentina in Abuja saw the hosts run out 4-1 winners against an under-strength Argentinian line-up.
Ike Uche scored twice and Victor Obinna once to put Nigeria 3-0 up at the break, while Emmanuel Emenike made it four in the second half.
Argentina then got on the scoresheet eight minutes into stoppage time, when only five had been signalled.
Joseph Yobo was penalised for a handball by referee Ibrahim Chaibou of Niger, and Wigan striker Mauro Boselli scored from the penalty spot.
It is claimed a high number of bets were placed for there to be another goal when the score was 4-0.
"Fifa can confirm that this match between Nigeria and Argentina was one that we had an active interest in, and forms part of a wider ongoing Fifa investigation," the world's governing body said in statement to the Daily Telegraph.