Police said a 20-year-old man had been arrested following Sunday's match at Parkhead.
The incident is said to have taken place in the stadium's toilets and police say they are liaising with the East End club's officials to identify any others involved in the incident.
A further 17 people were arrested in and around Parkhead and were charged with various minor offences.
The game was a sell-out with around 60,000 fans packing the stadium for a match which saw the home side win 3-0.





