Amateur video captured footage of travelling supporters forcefully preventing a black man from boarding a train before the Blues' 1-1 draw with Paris Saint-Germain.
Chelsea have condemned a section of their supporters who chanted a racist song and pushed a black man off a Paris Metro prior to the Champions League match with PSG.
The fans can then be heard singing a song that appears to celebrate the disgraceful behaviour, with lines including "We're racist, we're racist and that's the way we like it" whilst a black woman stands in close proximity.
The video was posted online shortly after the horrifying event and was picked up by the Guardian, who instantly published it on their website, leading to widespread condemnation of the footage. UEFA could now decide to punish the current Premier League leaders for their fans' behaviour.
The west London outfit, who could face a heavy fine, were quick to condemn those involved. A statement released by the club said: "Such behaviour is abhorrent and has no place in football or society. We will support any criminal action against those involved, and should evidence point to involvement of Chelsea season-ticket holders or members the club will take the strongest possible action against them, including banning orders."