Chelsea have suspended three supporters as part of the club's investigation into a racist incident on the Paris Metro.
A black commuter was pushed back by what appeared to be a group of fans travelling to the Parc des Princes for the Champions League match against Paris St Germain on Tuesday.
A chant of "We're racist and that's the way we like it" from the Chelsea fans was clearly audible on a video of the incident.
The supporters face life bans if they are found guilty.
Paris prosecutors confirmed that the alleged victim, identified in media reports as Souleymane, had made a formal complaint.
In an interview with Le Parisien, the man named by the newspaper as French-Mauritian Souleymane S called for those involved to be jailed.
He says he could not bear to tell his wife or children about what occurred at the Richelieu-Drouot Metro station.
"These people, these English supporters, have to be found, punished and should be locked up. What happened shouldn't go unpunished," he said.
Chelsea released a statement describing the incident as "abhorrent" and vowed to take the "strongest possible" action if supporters are found to be involved.