Charlton subs Danny Haynes and Emmanuel Frimpong took to Twitter claiming they were the victims of "disgusting" racial abuse at the match against Millwall on Saturday (Dec 1).
Haynes and Frimpong both alleged they had been racially abused by Lions supporters during the goalless game at The Den.
Mr Haynes’s tweet read: "The MILLWALL fans 2day was disgusting.The racial abuse I received was embarrassing. Not impressed at all!"
Lewisham Police say they are investigating the matter and a spokesman for Millwall confirmed the club was also investigating.
Charlton Athletic declined to comment.