Bolton striker Marvin Sordell has claimed he and several of his team-mates were racially abused by Millwall fans during his side's 2-1 defeat this afternoon at the Den.
The 21-year-old said on Twitter that he had reported the incident and revealed that midfielders Lee Chung-yong and Darren Pratley, plus fellow forward Benik Afobe, had also been subjected to racist taunts by some home supporters.
Sordell also received abusive responses to his allegations on Twitter.
Millwall later released a statement, saying: "Millwall and Bolton Wanderers are investigating allegations made by Bolton player Marvin Sordell that he was subjected to racial abuse by an individual whilst warming up as a substitute during Saturday's Championship clash at The Den.
"The two clubs remain determined to do everything in their power to ensure that racist behaviour will not be tolerated.
"We will be speaking to the police and the match officials on this matter but no further comment will be made until this process has been completed and the investigations have been concluded."
The Football Association tonight confirmed they would be investigating Sordell's claims.
Shortly after the FA's confirmation that they would investigate the incident, Bolton released a statement of their own.
It read: "Marvin Sordell has made Bolton Wanderers aware that he was subject to alleged racial abuse during the game against Millwall."We are now working with Millwall to investigate and the club have informed us that they will speak to the police and match officials.
"Both clubs remain determined that racist behaviour or language will not be tolerated."