In a further announcement from football leaks this week, Chelsea have been accused of making the illegal payment to the Danish international's father when he joined the club.
Danish paper 'Politiken' published the hacked files, which claim to show that Sten Christensen was hired as a scout on the same day that his son was purchased from Brondby in 2012 aged 15.
The copies of Chelsea's consultancy agreements show that Christensen Sr. received £11,400 per month plus VAT for four years, totalling £656,640, all while still being under the employment of Brondby, as a goalkeeping coach.
Danish media outlet 'Politiken' insists that there is no evidence that Christensen Sr did any scouting work in those years.
A spokesman for the Premier League told 'Sportsmail' on Thursday: "Should we receive any substantive material that indicates that our rules may have been broken, we will of course investigate it."
Meanwhile a spokesperson for Chelsea said: "We do not comment on speculation about confidential contracts or player-related cases."
The allegations come just one day after the club were among five Premier League teams to be allegedly under investigation from FIFA over possible rule violations regarding the signing of foreign players.