Police are looking into Vaclav Cerny's actions amid Rangers' winning goal celebrations against Celtic on Sunday.
The winger was spotted spraying Celtic fans near the away dugout with a water bottle amid the wild scenes close to the end of the derby match.
Hamza Igamane thundered the ball high into the net to give the visitors a 3-2 win in Glasgow's east end.
As the Sky Sports cameras panned to Barry Ferguson to get his reaction to the goal in the aftermath, Cerny was seen running down the trackside towards the away end while aiming the water bottle in the direction of the fans.
This resulted in a furious reaction from the Hoops supporters in that section of the main stand at Celtic Park.
Police officers and a heavy security presence were required to step in to help defuse the situation.
Now, the force have confirmed they are looking into the incident.
A Police Scotland spokesperson said: "Officers received information and enquiries are ongoing."
More to follow.
