Police are investigating a complaint that Celtic defender Virgil van Dijk was subjected to racial abuse during his side's victory at St Mirren Park.
The Dutch defender reported an incident to police following Saturday's Scottish Premiership match in Paisley, which Celtic won 2-1.
The 23-year-old acted after hearing chants from the crowd.
A police statement read: "Police Scotland has received a complaint from a Celtic player alleging he was racially abused by a spectator during the St Mirren v Celtic match on Saturday.
"Police are liaising with both clubs and are analysing broadcast and CCTV footage. Inquiries are ongoing."