Police are investigating threats and abuse against referee Michael Oliver after his decision to show a red card to Arsenal's Myles Lewis-Skelly during Saturday's win at Wolverhampton Wanderers, Professional Game Match Officials Limited (PGMOL), a referee's organization in England, said Sunday.

Lewis-Skelly was sent off for tripping Matt Doherty on the edge of the Wolves' box, leaving Arsenal coach Mikel Arteta "fuming" over the decision, which was upheld by VAR. The red card was Arsenal's fourth of the season.

"We are appalled by the threats and abuse directed at Michael Oliver following the Wolverhampton Wanderers v Arsenal fixture," the PGMOL said.

"No official should be subject to any form of abuse, let alone the abhorrent attacks aimed at Michael and his family over the past 24 hours.

"The police are aware, and a number of investigations have commenced. We are supporting Michael, and all those affected, and are determined to tackle this unacceptable behaviour."

The Premier League said in a statement the red card was "checked and confirmed by VAR who deemed Lewis-Skelly's challenge to have been serious foul play." The defender will be suspended for three games.

Television pundits, however, reacted with surprise at Oliver's decision, and former Premier League referee Mike Dean said a yellow card would have been sufficient.