The head of the Serbian Football Association is being investigated by Fifa over an interview he gave to the BBC in which he accused the governing body of bias against his country.
Slavisa Kokeza’s comments followed Friday’s World Cup loss to Switzerland.
Head coach Mladen Krstajic is also being investigated for statements he made in the aftermath of the game.
Meanwhile, Stephan Lichtsteiner has become the third Swiss player to be investigated over a goal celebration.
He joins team-mates Granit Xhaka and Xherdan Shaqiri, who are the subject of disciplinary proceedings after making politically-motivated gestures during their celebrations.
Speaking to the BBC on Saturday, Kokeza said Serbia were victims of a “brutal robbery” during the 2-1 defeat and said Fifa had “directed” officials to work against them.
He was unhappy a German referee had been appointed for a game involving Switzerland – which has a predominantly German-speaking population.
He claimed the move influenced some decisions, most notably the failure of the match official and video assistant referee (VAR) to award a penalty when Aleksandar Mitrovic was wrestled to the ground by two Swiss players.
Fifa has also fined the Danish FA 20,000 Swiss francs (£15,250) for crowd disturbances, a sexist banner displayed by fans and not respecting pre-match protocol in the 1-1 draw with Australia.
Disciplinary proceedings have been opened against Germany team officials Ulrich Voigt and Georg Behlau for an incident at the end of the 2-1 win against Sweden on Saturday.