The National Crime Agency has launched a match-fixing investigation into Wednesday's friendly between Scotland and Nigeria at Craven Cottage.
It is understood that the Scottish Football Association has been working with the NCA after concerns were raised about the fixture.
Nigeria travel to London ahead of their participation at next month's World Cup in Brazil. Despite the developments, the game is due to go ahead.
FIFA are expected to brief players on what to do if they are approached to fix a match during the tournament in South America, according to The Telegraph.
All 32 nations competing in Brazil will be told to report any suspicious activity via an anti-corruption hotline that is only available to players and officials.
