Anti-racism chief Piara Powar believes the episode involving Chelsea supporters blocking a black man from boarding a Paris Metro train is a consequence of a wider problem in football and pointed to racist comments made by prominent figures in the game.

Chelsea have vowed to support criminal prosecutions and ban any fans after footage, posted on the Guardian website, showed a commuter attempting to board a Metro train in the French capital.

He is blocked by what appears to be a group of Chelsea fans travelling to the Parc des Princes for Tuesday night's 1-1 draw with Paris St Germain.

The match, deemed to be high risk by UEFA and Football Against Racism in Europe after a number of incidents surrounding last season's fixture, took place in a week when former Italy coach Arrigo Sacchi said there were "too many black players" in Italian football.

FARE executive director Powar told Press Association Sport: "We are seeing a lot of football leaders who are making racist comments.

"There's a whole range of people in prominent positions in football who are making out and out racist comments. The comments by Arrigo Sacchi and before Sacchi we've had Carlo Tavecchio, Willy Sagnol, Dave Whelan, Malky Mackay. We've had John Terry, Luis Suarez.

"One feels that this is one of the things that keeps the link between racism and football alive.

"If these guys are prosecuted in a criminal court they might argue 'well, we hear this going on at top level, why can't we express similar sentiments?'

"This is the big challenge that football has: how do you deal with the big issue of racism at the top level, from football leaders across Europe, and therefore begin to unpick the wider issues of racism that we have?"

Powar believes the lack of ethnic minority individuals in senior positions in the game is also a contributory factor.

He added: "I also see a link between the lack of black and other ethnic minority leaders in football, so people don't respect ethnic minorities, except as players. It's about the wider picture at the moment."

It has been suggested the Rooney Rule - used in the NFL to ensure ethnic minority candidates are adequately represented in the interview process for head coaching positions - should be applied in football.

When asked about the Rooney Rule last October, Chelsea boss Jose Mourinho said: "There is no racism in football. If you are good, you get the job. Football is not stupid to close the doors to top people."

Clearly Mourinho was referring to those within the game and not supporters, while Chelsea have worked to eliminate discrimination from the club and Saturday's Premier League match at home to Burnley has been designated a 'Game for Equality'.

Chelsea released a statement condemning the incident and said they will take action if supporters are found to be involved.

"Such behaviour is abhorrent and has no place in football or society," a club spokesman said.

"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 are working with the relevant authorities to identify if those involved have season tickets or any other connection to the club.

One fan who witnessed the incident has defended the actions of the group, insisting they were singing about Blues captain Terry and that other passengers were blocked from entry.

Mitchell McCoy was one of around 40 or 50 Chelsea supporters on the train and he stated they were singing about Terry, who was banned for four matches and fined £220,000 by the Football Association in October 2012 for racially abusing Anton Ferdinand. In Terry's case, the regulatory commission stated that the Chelsea captain was "not a racist".

McCoy, a season-ticket holder who travelled to Paris with five friends, was named on Twitter following the publication of the video.

A chant of "We're racist and that's the way we like it" is clearly audible on the video, but McCoy contended it was not about the passenger barred from entry.

The 17-year-old from Fulham told Press Association Sport: "That song was about John Terry. The only words I know is 'he's a racist, he's a racist' and I don't know the rest."

Asked why that song was sung at that moment, he said: "I'm not sure. I didn't sing it."

Former England striker Ian Wright called for more to be done and wrote on Twitter: "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."

Powar added: "The starkness of this brings a hope and expectation that it wakes people up, reinforces the need for education and to keep taking action whenever this sort of stuff occurs."

FIFA president Sepp Blatter, UEFA, the Football Association, Kick It Out, the Football Supporters' Federation and Chelsea Supporters' Trust all condemned the incident, which UK police are investigating.

Prime Minister David Cameron said the incident appeared to be "extremely disturbing and very worrying".

"It's obviously potentially a criminal offence and so I'm sure the French police will be looking at it very seriously," he told LBC radio.

"I know the British police will give every assistance that they can. I'm sure Chelsea will co-operate with that fully. These are very, very serious matters."

Chelsea have appealed for witnesses regarding the incident on the Metro and also of a separate one outside the stadium which saw a number of Blues fans affected by CS spray.

A Chelsea statement said: "Chelsea Football Club is aware of an incident in Paris last night (Tuesday) when a number of our supporters were affected by CS spray outside the Parc des Princes before kick-off.

"We are emailing fans who purchased tickets directly from the club asking for witness accounts of the incident.."