Not a conspiracy — but it turns out Jose Mourinho may have a point about Chelsea, penalties and Barclays Premier League referees after all.

Statistical analysis provided by Opta shows an incredible discrepancy between the number of penalties Chelsea receive in Champions League games and the amount they are awarded in domestic league competition.

In seven UEFA fixtures this season, Chelsea have won four penalties, at a rate of one every 1.8 matches. Very high. In the Premier League, this skips to just two penalties in 26 games, at a rate of 13.

Jose Mourinho claims that his Chelsea side do not get the refereeing decisions they deserve

Chelsea's Diego Costa appears to get pushed over by Jason Shackell in the recent 1-1 draw with Burnley

Costa looks bemused after Martin Atkinson refuses to award him a penalty after the tussle with Shackell

Chelsea were denied another penalty against Burnley when Branislav Ivanovic's shot hit Michael Kightly's arm

What makes the statistic so curious is that, for the other clubs, the rate at which penalties are won in the Premier League and Champions League barely differs.

Manchester City and Liverpool also find it harder to win penalties in the Premier League but only by a variation of 0.2 and 0.5 respectively.

Arsenal actually find it almost twice as easy to earn penalties in the Premier League as they do in Europe, but even then the gap between the competitions only equates to 3.3 matches.

Yet Chelsea take a whopping 11.2 additional games to win a penalty in the Premier League, compared to their European form.

It represents the first corroborative evidence that Mourinho’s fears his team are getting a raw deal may have substance.

It makes no sense that the team that has won most Premier League matches, has the best goal difference and ties with Manchester City for the most goals scored, is not picking up as many fouls in the penalty area.

Chelsea and Manchester City have both scored 56 league goals this season. That’s a lot of attacking play.

Jose Mourinho asked specifically to be a guest on television show Goals on Sunday to air his grievances

Mourinho launched into a 27-minute rant against numerous parties he believed to have wronged Chelsea

Eden Hazard is fouled by Arsenal's Laurent Koscielny, leading to one of Chelsea's two league penalties

Ivanovic is hauled to his feet by West Ham players after going down in the box at Stamford Bridge

Yet while City are awarded a penalty every 3.7 games, such an opportunity for Chelsea comes around once every 13. Maybe Mourinho is aware of this anomaly and it is fuelling his belief that there is a campaign against his team.

Those not wrapped in Chelsea blue will still find it hard to believe that there is a conspiracy against the league leaders — who would be behind it and what would be the purpose?

Yet, certainly, numbers as illogical as this will merely confirm the feeling at Stamford Bridge that they have been unfairly treated too often this season, and it could cost them with the gap at the top now down to five points.

Yes, the margins are small. Had a foul on Diego Costa at Burnley and another on Cesc Fabregas at Southampton been spotted — both players were wrongly booked for diving instead — then Chelsea’s aggregate would have fallen to 6.5 in the league, still high but at least in the ball park.

A ratio of 13, however, suggests a flawed process, worthy of conversation between the club and referees’ chief Mike Riley.

Something is not right. Not a conspiracy, but without doubt it doesn’t add up.

Additional reporting by Barry Bwana

Chelsea have won many more penalties in the Champions League than they have in the Premier League

Referee Martin Atkinson has been backed by the referees’ assessor for his handling of Chelsea's game

Mourinho was also angry over the dismissal of midfielder Nemanja Matic by Atkinson against Burnley