Manchester United are awaiting feedback from Uefa after reporting the referee who took charge of their Europa League win over Feyenoord on Thursday.
Manuel Gräfe, the German ref who also oversaw West Ham United's European exit at the hands of Astra Giurgiu in August, reportedly refused to be searched ahead of the group stage fixture.
According to the
Mirror, Gräfe went straight to the referee's room despite stadium security attempting to conduct a search, as they do with anyone entering the ground.
It is unclear whether or not the mandatory searches are related to the bomb scare at Old Trafford at the end of last season, when United's Premier League meeting with Bournemouth was postponed amid what later transpired to be
the remnants of a training exercise.
The German referee has taken charge of games involving English teams before (Ian Walton/Getty Images)
United beat their Dutch opponents with minimal hassle, scoring four times without reply to ensure their European fate remains in their own hands.
Henrikh Mkhitaryan impressed in a rare start, while Wayne Rooney returned to form with a delightful early finish and backup goalkeeper Sergio Romero made a couple of important saves.
Victory for United in their final Europa League group game against Zorya Luhansk will ensure their progress to the knockout stages, and could see them top the group depending on Feyenoord's result against Fenerbahçe.
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