Manchester United have reported referee Manuel Grafe to UEFA,before their Europa League tie with Feyenoord after the German refused to be searched by security officials, according to reports in theMirror.
United cruised to a comfortable 4-0 win over the Dutch side, but it was the events before the match that led to their complaints about the referee's behaviour.
EXCLUSIVE: #MUFC report referee to #UEFA after security breach https://t.co/ltoZbjFrgb
Grafe, who is recognised as one of UEFA's top officials, is understood to have refused permission to allow a security official to search him when he entered Old Trafford.
Despite United's chief security officer being called to defuse the situation, Grafe insisted he had never been asked to be searched and continued to refuse the request of a mandatory search.
Following the completion of the game, the home team are believed to have reported Grafe to UEFA's delegate for the match,Alnar Leppanen.
The German referee has since apologised for the incident but insistedhe is innocent, as he has never been asked to submit to a searchbefore a match.
Officials at Old Trafford are believed to betightening security measures, after news emerged last week that two members of the public were able to hideout in one of the stadium's toilet facilities overnight in a bid to watch the following day's game between United and Arsenal.
Two fans hide in toilet overnight for chance to watch Man U game - and nearly get away with it https://t.co/D4AIIUqkcv
Although the pair were both caught, it has raised new questions over the security procedures at Old Trafford, just months after a Premier League clash between United and Bournemouth was cancelled due to a bomb scare.
It was later revealed the bomb was a fake and had accidentally been left by a security company conducting a training exercise, days before the match was set to take place.