Police are investigating an allegation of racist abuse after Manchester City star Aleksandar Kolarov became involved in a heated exchange with a spectator at St James' Park.
Northumbria Police confirmed they received a complaint in the wake of City's 3-1 Barclays Premier League victory at Newcastle on Saturrday.
A spokesman said: "Northumbria Police has received a report of racist language having been used at the St James' Park stadium during the Newcastle United v Manchester City match today.
"Northumbria Police takes such allegations extremely seriously and inquiries are ongoing into the incident."
It is understood 27-year-old Serbia international Kolarov became involved in a lengthy exchange with a supporter carrying an Albania flag as he warmed up on the sidelines during the game.
There is a long history of tension between Serbia and Albania, particularly over the disputed Kosovo region.
Neither club was commenting on the matter, although it is understood that Kolarov will be spoken to by police this week.
The defender was introduced as a 37th-minute replacement for the injured Samir Nasri, but was also substituted 18 minutes from time.