London, Apr 11 (IANS): Premier League assistant referee Constantine Hatzidakis will not be involved in another game until the end of an investigation over an incident where he appeared to deliberately elbow Liverpool defender Andrew Robertson.

The Professional Game Match Officials Limited (PGMOL), who governs referees in English football, said on Monday it was investigating the bizarre incident at halftime in Sunday's 2-2 draw between Liverpool and Arsenal.

TV images show that Robertson approached Hatzidakis moments after referee Paul Tierney blew for halftime, only for the official to appear to use his elbow against the left back, who was subsequently shown a yellow card by Tierney, a Xinhua report said.

At the time the PGMOL said it was "aware of an incident involving assistant referee Constantine Hatzidakis and Liverpool defender Andrew Robertson at half-time during the Liverpool vs Arsenal fixture at Anfield," adding they would "review the matter in full once the game has concluded."

On Monday they issued another statement explaining they would "not be appointing Constantine Hatzidakis to fixtures in any of the competition it serves whilst The FA investigates the incident involving the assistant referee and Liverpool defender Andrew Robertson at Anfield."

Speaking after the final whistle, Liverpool coach Jurgen Klopp preferred not to discuss the incident, saying: "I know it happened but I didn't watch it. If it happened, the pictures will speak for themselves."