Chelsea head of communications Steve Atkins has issued a statement on behalf of the club to condemn the incident that occurred on the Paris Metro on Tuesday night.
A video captured a group of Chelsea supporters preventing a black man from boarding a train before verbally supporting their actions, and after the Stamford Bridge outfit suspended three people potentially involved in the incident, the Premier League leaders have apologised "unreservedly" to the man involved.
Atkins said: "On behalf of everyone at Chelsea Football Club, I would like to make it clear our disgust with regards to the incident that took place on the Paris Metro on Tuesday evening.
"We were appalled by what we saw. The club would also like to apologise unreservedly to Souleymane for the behaviour of a small number of individuals and their unforgivable actions towards him.
"We have been cooperating fully with the Metropolitan Police and Paris Police during their investigation and we will continue to do so.We have also been conducting our own investigation and all information from that is being shared with those police forces.
"We announced last night that we have suspended three individuals from Stamford Bridge, pending the completion of our investigation. Should evidence show that they are guilty in that incident, the club will ban them for life.
"It is only right that we complete our investigation to establish all of the facts of that evening, but we have taken swift and decisive action on the information that we have received so far.
"The people involved in the incident in Paris do not represent Chelsea Football Club. They do not stand for the values of this club and they have no place at this club.
"This has been echoed loud and clear by the vast majority of Chelsea supporters. We would like to thank the many Chelsea fans that have come forward with information in this case. We are a club that are proud of its diversity. We work extremely hard in the game and in our communities to promote equalities and fight discrimination of all forms.
"We are proud to support 'Kick It Out' and 'Show Racism The Red Card' among other organisations and we work closely with similar programmes with the Football Association and Premier League."
Manager Jose Mourinho has also revealed that he felt "ashamed" when he was first made aware of the incident.