NFF axed a second-division game between Ullensaker/Kisa and Ham Kam on Sunday over fears of outside interference aimed at fixing the result.
Third-tier team Follo also reported suspicions of match-rigging to NFF after a second-half collapse in its game against Østsiden saw the team shed a 3-0 lead in a match that ended 4-3 to the opposition.
Large bets were made on the game shortly before kickoff on June 24th.
Police are also expected to investigate a match played the same day between Asker and Frigg after Asker reported its 7-1 defeat as suspicious.
“NFF and the clubs want to assist the police to the best of our ability, which also means we are unable to comment on specifics relating to the case in light of the investigation,” said NFF president Yngve Hallén in a statement on Sunday.
Speaking to newspaper Verdens Gang, NFF confirmed it had received information that the alleged match-fixing scheme was organized by mafia groups in Sweden with ties to the Balkan region.
“That information could be true or false,” said NFF secretary general Kjetil Siem.
The newspaper said a number of other centrally placed sources also claimed Sweden-based organized crime groups had approached players in Norway in an attempt to fix matches.