Derby midfielder Bradley Johnson has been handed an increased four-match ban for allegedly biting Stoke's Joe Allen, the Football Association has announced.

The incident, which occurred during Derby's 2-1 defeat at the bet365 Stadium on Wednesday, was not seen by any of the match officials at the time.

"Bradley Johnson has been suspended for four games after he was found to have committed an act of violent conduct for which the standard punishment would be clearly insufficient," the FA said in a statement.

"The Derby County player was involved in an incident with Stoke City's Joe Allen during Wednesday's game (November 28)] which was not seen by the match officials but caught on camera.

"Johnson denied the charge of violent conduct with an Independent Regulatory Commission then considering The FA's allegation that the three-match sanction should be increased.

"In addition to the suspension for violent conduct, the player will also serve a one-match ban for accumulating five cautions."

Johnson, 31, was caught on camera grabbing Allen's shirt with his teeth during a fracas after Stoke midfielder Peter Etebo had been sent off.

But Allen defended Johnson after the match, claiming he had not been bitten.

"He might have got a little bit of the shirt but nothing that I'm worried about and I don't think it should go any further than that," Allen said.

Both players were booked by referee Darren England for their part in the melee.

When incidents such as this are missed by the referee and his assistants they are referred to a panel of three former elite match officials.