In-depth: Will Chelsea ever throw off the spectre of fans' racism?

That was the horrifying chant of the Chelsea fans as they boarded a Metro train in Paris on Tuesday night after their team's match in the French capital. And to back up their words with actions, they prevented a black French commuter from boarding the busy train.

The Blues were probably expecting positive headlines after their last-16 Champions League draw with French giants Paris Saint-Germain. Instead, the focus has been on a section of the club's supporters filmed singing a racist song while preventing a black man from boarding the Paris Metro.

The Blues are owned by a Russian billionaire, managed by a Portuguese coach and feature some of Africa's most prominent footballers, including Didier Drogba and John Obi Mikel. For years they have been one of the most multi-cultural sides in the Premier League.

Yet in the 1980s the club's supporters were, alongside Millwall, perhaps the most notorious in the country for racism and hooliganism. The horrendous scenes in Paris strongly suggest - and not for the first time - that there remains a deeply unpleasant element among the Chelsea supporters.

The club quickly distanced itself from the supporters on the train, saying, "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."

Chelsea themselves were far from the only ones condemning the incident, with Chelsea fanzine editor David Johnstone saying, "I think the majority of Chelsea supporters are disgusted by what’s happened."

I also condemn the actions of a small group of Chelsea fans in Paris. There is no place for racism in football!— Joseph S Blatter (@SeppBlatter) February 18, 2015

But Kick It Out chairman Lord Ouseley spoke for many people when he spoke to the Press Association, announcing that he was shocked at Chelsea fans "still" behaving like this - a reference to both their players and fans being involved in a handful of racial-related incidents over the years.

“I was shocked that Chelsea fans were still behaving like this. I thought the club had made it quite clear and taken action about stopping any repetition, knowing Chelsea, how hard they’ve worked on these matters, with fans as well as players, that it was unlikely to occur."

To fans above the age of 30 such words will strike home (as will Ian Wright's Tweet, below), because Chelsea's fans were once nothing short of notorious. As an Economist correspondent (and Chelsea fan) wrote in 2012, "Many were skinheads; footsoldiers of extreme right-wing parties such as the National Front and the British Movement."

Those guys on the train remind me of my childhood. Chase you with their mates! But when alone and confronted, I've seen them cry. 😂😂😂😂— Ian Wright (@IanWright0) February 18, 2015

As upsetting as video of Chelsea fans is not sure why we are surprised. You may not hear racists chants in stadiums today, but not gone away— tariq panja (@tariqpanja) February 18, 2015

In one famous incident Paul Canoville was abused by his own fans as he warmed up before making his Chelsea debut in 1982 - a far from uncommon fate for black players at Stamford Bridge, the treatment not withheld even for a promising new player.

As football has become gentrified over the last 20 or 30 years, with Chelsea boasting many prominent fans in the media and politics, the reputation of the club has changed, and those extremist fans have become far less prominent.

But they are still there, and even in the last dozen years there have been a number of disturbing incidents:

- In 2003, a poll in the Times newspaper said 47% of Chelsea fans have witnessed racist behaviour among their fans.

- In 2007, a section of Chelsea fans were heard singing racist and anti-Semitic chants towards new manager Avram Grant

- In 2008 Patrice Evra was banned for four matches and fined £15,000 for his role in a post-match fracas with the Chelsea groundsman. It was alleged that Sam Bethell had called Evra a "f***ing immigrant" and although the club were fined £25,000 for the attack, the allegation of racism was dismissed.

- John Terry was banned for four matches for racially abusing QPR defender Anton Ferdinand in a match in October 2011.

- In the 2011/12 season, Chelsea had the most supporters arrested for racist or indecent chanting (23 fans).

The Chelsea Headhunters football hooligan firm have built a large reputation on their affiliation with white supremacist organisations including the National Front and Combat 18.

Investigative reporter Donal MacIntyre produced a documentary on the group in 1999 when he posed as a wannabe-member of the Headhunters.

He confirmed the racism in the Headhunters and revealed one top-ranking member has been imprisoned on one occasion for possession of material related to the Ku Klux Klan.

A Goal.com feature by Ron Shillingford explored how the racism furore surrounding John Terry and Anton Ferdinand showed that "English football has not completely kicked racism into touch".

Reaction on social media was generally horrified.

Watching the Paris Metro Chelsea fans video, I just keep thinking who are these terrible people and what do they do when they go home?— Midland (@midlandsound) February 18, 2015

I wonder if those Chelsea fans in Paris celebrated when Drogba's penno won them the Champions League?— Sime (@yyydelilah10) February 18, 2015

Just saw the video of the Chelsea mob's deplorable behaviour and racist chants. Sickening, embarrassing, moronic, disgraceful.— Gary Lineker (@GaryLineker) February 18, 2015

Chelsea FC confirm banning orders and criminal action against those on the video. Good.— Stan Collymore (@StanCollymore) February 18, 2015

Several commentators on Twitter even referred to the John Terry - Anton Ferdinand case - and specifically the argument with which he successfully avoided public prosecution (despite the fact that the FA later found him guilty of racist abuse):

Apparently those Chelsea fans were sarcastically repeating a chant from the man who they prevented getting on the train.— Alexander Netherton (@lxndrnthrtn) February 18, 2015

Chelsea should make those fans captain.— Daniel Harris (@DanielHarris) February 18, 2015

Notoriously, Chelsea stood by Terry as their captain after that incident:

It's good that Chelsea have condemned their racist fans. It's a shame this is undermined by them failing to condemn their racist captain.— Scott (@R_o_M) February 18, 2015

Chelsea condemn their fans, but retention of their captain in '12 after FA found he'd racially abused opponent raises q's of consistency— Dan Roan (@danroan) February 18, 2015

No doubt Chelsea football club will seek to allay such concerns by banning the fans concerned, and fully supporting the French authorities' efforts to prosecute.

But even if they were to do so, it still feels like there is a long way to go before the club can truly sweep away the bigotry and intolerance that still rule the hearts and minds of many of their fiercest and most loyal fans.