Chelsea have launched an investigation after a photograph emerged of a supporter appearing to make a racist gesture towards a Manchester United player.

The image shows a fan making what has been described as a "monkey" gesture during Wednesday night's Capital One Cup match between the two clubs at Stamford Bridge.

The Metropolitan police have confirmed they have also launched an investigation into the incident after a complaint was received, adding: "There have been no arrests and enquiries continue."

A statement from the club read: "Chelsea Football Club can confirm we are investigating an incident involving a member of the crowd at last night's game against Manchester United.

"The club will be examining all available footage and asks anyone who can identify the individual to contact the club.

"Chelsea FC is committed to removing all forms of discrimination and if we have sufficient evidence we will take the strongest possible action, including supporting criminal prosecution."

This latest issue comes at a sensitive time for Chelsea, with the club having lodged a formal complaint with the Football Association against the referee Mark Clattenburg for using "inappropriate language" towards the midfielder Mikel Jon Obi. Clattenburg maintains his innocence.

Chelsea are also understood to be looking into a number of incidents concerning United fans after objects were thrown onto the pitch during the match and a pitch invasion involving an away supporter.