A thug caught on camera was seen using a Nazi salute at the Manchester City v Lyon game last night.
It is expected once found the French club will ban him from all games home and away.
Police are aware of the video that has been circulating on social media believed to be filmed at the MCFC v Lyon match last night Sept 19.
The salute by the fan is being treated as a hate crime and enquiries are ongoing.
Manchester City lost the game 1-2.
Chief Inspector Gareth Parkin Silver Commander of the Manchester City v Lyon fixture said: “This is absolutely abhorent behaviour and has no place in our community, and no place in sport.
“We are committed to policing racism at football matches, and hate crimes of any sort will simply not be tolerated.
“We will be working closely with French police and both clubs to identify the person responsible.”
Anyone with information should contact police on 101, or anonymously to Crimestoppers on 0800 555 111.