Racism is widespread in English football with police having to deal with hundreds of incidents from the top of the game right down to grassroots level, an investigation has revealed.

It also revealed that Chelsea supporters have been involved in the highest number of reported racist incidents as they travelled to and from matches on trains.

It follows the high-profile case of a black man who was prevented from boarding a train in Paris by Chelsea fans as they sang a racist song, with five of them due in court this week.

Chelsea supporters have been involved in the highest number of reported racist incidents

The information, gathered from 24 police forces across the country, shows there have been over 350 incidents since 2012.

But as that only accounts for around half the police forces in the country, the actual figure is likely to be much higher.

The charity Show Racism The Red Card said the number of incidents shows that racism is a societal problem and it was particularly shocked by the number of incidents of racist abuse at children's matches.

The British Transport Police said since 2012 it had dealt with 15 incidents of alleged racism involving Chelsea fans, the most of any club in the country.

Manchester United were second with 10 incidents, followed by Leeds with 10, West Ham with eight, Arsenal with four and Portsmouth with four.

Chelsea fans united with a banner stating 'Black or white, we're all blue' ahead of Burnley match

A club spokesman for Chelsea said of the investigation: 'The club's position on discriminatory behaviour is clear and we work closely with relevant authorities on their investigations.'

Greater Manchester Police reported 46 incidents, which included a man cleaning a toilet in a stadium being told 'that's a f****** black man's job, you f****** n*****' and a manager at a children's game being told 'I'll do you, I'm gonna wait for you outside, I'm going to do you, you f****** n*****'.

The force also said that on two occasions a letter was written to a specific footballer containing racist abuse and during a game someone shouted 'what is this the United Nations, how many chinks and w*** do you need?'.

Hertfordshire Police recorded 11 incidents of alleged racist abuse at children's football games, while Northamptonshire Police said that during a non-league game a man was spat at and racially abused before eventually having his leg broken in a strong challenge.

Some Chelsea fans were involved in an incident on the Paris Metro, and supporters have worked hard in the aftermath to show that there is no racism at Stamford Bridge

Gavin Sutherland, campaign co-ordinator at Show Racism The Red Card, said: 'This data from police forces around the UK shows that although football clubs have taken strong action against people using racist language inside stadiums, racism is a real problem within society.

'People who exhibit racist behaviours in 2015 are doing so, in the main, away from football grounds.

'Especially worrying are the incidents of racist abuse at youth team football matches. People engaged in racist abuse at these venues know that they are more likely to get away with it, because of facilities, a lack of stewarding and security, but the impact on young people will be considerable.

'Primarily, they are being exposed to racism, which in itself is frightening, but also it may influence their own behaviour.'

Other incidents included Cleveland Police reporting repeated monkey sounds and gestures during a Middlesbrough v Blackburn game in November last year and Devon and Cornwall Police said a man was headbutted and racially abused during a non-league game.

Chelsea's programme cover for the match against PSG carried a clear message: 'We are all blue #equality'

Surrey Police said a referee received racist insults during a kids' game and Essex police said a footballer refused to shake hands with a player from the opposite team before racially abusing him.

Due to the fact that some police forces were unable to provide the information or did not reply to the request, Mr Sutherland said there would certainly be a greater number of cases.

'These incidents, although shocking in themselves and how geographically widespread they are, will be just a part of the picture,' he said.

'These are the incidents that have been reported. There will certainly be a greater number unreported and under-investigated.

'Show Racism The Red Card has always stated that the reason racism manifests in football is that it is a societal problem.

'The campaign works with young people and adults not just to educate against racism, but encourage the use and development of critical thinking skills to break down the misinformation that supports racist beliefs.'