The FA and refereeing body PGMOL have launched an investigation into the extraordinary scenes at Anfield on Sunday which appear to show Liverpool full-back Andrew Robertson being elbowed in the face by a linesman.

Liverpool recovered from two goals down to draw 2-2 with Premier League leaders Arsenal on a thrilling afternoon to leave Mikel Arteta’s side six points above Manchester City with a game in hand.

But it was the events at half-time that stole the headlines in what appeared to be an unprecedented clash between a match official and a Premier League player.

As Robertson walked off the pitch to the players’ tunnel, he appeared to say something to assistant referee Constantin Hatzidakis, touching him lightly on the right elbow. Hatzidakis responded by elbowing Robertson in the face.

The official may claim he was just shrugging off Robertson’s shoulders, but the Scotland international was left holding his chin as if to say: “He just elbowed me in the throat. The scorer hit my throat with his elbow.

Robertson left after reportedly being hit in the throat at halftime

PGMOL has confirmed it will review the incident involving linesman Constantine Hatzidakis.

Before the game ended, the PGMOL, now chaired by former Premier League referee Howard Webb, issued a statement saying they would investigate.

PGMOL is aware of an incident involving assistant referee Konstantin Hatzidakis and Liverpool defender Andrew Robertson during half-time at Anfield between Liverpool and Arsenal.

“After the end of the game, we will review the issue completely.”

It is also understood that the FA will look at the matter in much the same way as it would if the player was at fault away from the match referee’s attention.

Such an act is usually classified as “violent conduct” and carries a three-game suspension.

“Liverpool” head coach Jurgen Klopp said. “I haven’t seen it and I obviously have time to watch it now, but I haven’t.

“I cannot give wrong answers. I heard the pictures speak for themselves. I can’t say more. I didn’t see a bit of it.

Sky’s TV pundits are divided on the issue.

Liverpool hit out at referee Paul Tierney after alleged linesman incident

Sky Sports pundits Roy Keane and Gary Neville reviewed the incident at half-time

The video showed Robertson’s teammates reacting to the alleged collision

Former defender of “Manchester United” Gary Neville said. “I have never seen an official raise an elbow to a player. I think he’s going to be in a lot of trouble when the game is over.”

But Neville’s former United captain Roy Keane believes Robertson may have provoked the official.

Keen said: “Does he catch the lineman first? I’m not sure, but Robertson is complaining at the time. He should worry more about his defense.

“Do you know who he is, that Robertson?” I’ve watched him a few times, he’s a big kid. That’s what that guy is.

“Just focus on the game and keep defending. He catches the linesman first.