Liverpool are looking into the claim, the BBC and Sky Sports said, after the Premier League rivals shared the points following a breathless second half that saw City twice come from behind.
“They (my staff) told me but I didn’t see it,” City boss Pep Guardiola said of the alleged incident, according to the BBC.
“I’m pretty sure Liverpool FC will take measures against this person. I know they are greater than this behaviour.”
Mohamed Salah appeared to have won the game for Liverpool with a cracker at a frenzied Anfield on Sunday after Phil Foden had cancelled out Sadio Mane’s opener, but Kevin De Bruyne’s late deflected shot rescued a point for Guardiola’s men.
The result leaves the Premier League title race tantalisingly poised, with Liverpool a point behind leaders Chelsea, and City in third place, two points off the top alongside a clutch of other clubs.
Chelsea were the only side in the top six to win this weekend, seeing off Southampton 3-1.