Two Manchester United fans spent Friday night undetected in an Old Trafford toilet in an attempt to see Saturday’s Premier League game against Arsenal.
The supporters had been on a stadium tour but managed to cut themselves off from the remainder of the party.
They were found on Saturday morning during a security sweep of the stadium before being handed over to police, who decided not to arrest the pair.
United say there was no risk to supporters attending the Arsenal game.
The pair had been searched and their belongings put through a metal detector before they went on the tour.
The incident comes six months after United’s Premier League game against Bournemouth at Old Trafford had to be called off at short notice when a suspect package was found in a toilet in the corner of the stadium.
It turned out to be a fake explosive left behind after a training exercise earlier in the week.