Dylan Hartley will not face disciplinary action after Leicester's Tom Youngs claimed he was bitten during Saturday's 22-16 win at Northampton.
Youngs reacted furiously towards the Northampton Saints front-row after a scrum broke up early in the match.
Saints director of rugby Jim Mallinder said later he would speak to Hartley, the club captain.
But an RFU spokesperson said: "The incident has been reviewed and no action will be taken against Hartley."
It appears the lack of evidence to support Youngs's allegation and the absence of any complaint from Leicester Tigers has led to a decision by citing officer Andy Blyth not to take action after he reviewed footage.
Referee Wayne Barnes referred the 15th-minute incident from Saturday's game to television match official Trevor Fisher after hearing an unnamed player's allegation on the pitch.
Leicester boss Richard Cockerill confirmed Youngs's claim that he had been bitten by an opponent but stopped short of identifying a culprit.
"Tom said that he was bitten on the hand by someone he didn't elaborate on," Cockerill said on Saturday.
It was unclear whether Mallinder had intended speaking to Hartley, an England team-mate of Youngs, because of his role as captain or because he was under suspicion.
"I don't think there was anything in it," Mallinder said. "I would be very surprised."