The German Football Association (DFB) is investigating comments made by Borussia Dortmund's Jude Bellingham after the English midfielder criticised the referee Felix Zwayer following Saturday's Bundesliga defeat by Bayern Munich.

Zwayer turned down Dortmund's appeals for a penalty before awarding one to Bayern following a handball from Mats Hummels. Robert Lewandowski scored from the spot to give Bayern a 3-2 win.

Dortmund coach Marco Rose and several players were left fuming over the decision which allowed Bayern to extend their lead at the top of the Bundesliga table to four points.

"For me, it wasn't (a penalty). He (Hummels) is not even looking at the ball and he's fighting to get it and it hits him," Bellingham told Viaplay.

"You can look at a lot of the decisions in the game. You give a referee, that has match-fixed before, the biggest game in Germany. What do you expect?"

Zwayer was named in a 2005 scandal involving referee Robert Hoyzer, who was jailed for fixing matches in a €2million betting fraud that caused huge embarrassment to Germany ahead of the 2006 World Cup it hosted.

The DFB had banned Zwayer for six months for accepting €300 from Hoyzer and agreeing to make incorrect decisions in a match when he was an assistant referee.

The DFB said in a statement that its control committee has written to Bellingham and asked him to comment on his statements as soon as possible.

It added that the committee will decide what action to take once Bellingham's response has been evaluated.

Dortmund chief executive Hans-Joachim Watzke told Kicker magazine he fully supported Bellingham.

"That was a highly emotional situation, he was very disappointed and only stated known facts," Watzke said.