It's the highest profile match yet in a wave of recent suspicious international friendlies.
FIFA says Wednesday's match in Lagos ''was one that we had an active interest in, and forms part of a wider ongoing FIFA investigation.''
Referee Ibrahim Chaibou of Niger awarded two penalties, including one scored by Argentina in the eighth minute of second-half stoppage time.
Television replays suggested there was no handball offense by Nigeria as Chaibou indicated.
Hours before kick off, FIFA President Sepp Blatter launched his ''Zero Tolerance'' campaign to stop corruption.