Chelsea have declined to comment on an allegation of illegal payments made to Andreas Christensen's father.
Danish publication Politiken on Thursday published the details about the Denmark defender's move to London six years ago, which were obtained through Football Leaks.
It is claimed Sten Christensen joined Chelsea as a talent scout on the same day his son signed for the Blues, which was July 1, 2012, the opening day of the transfer window following his 16th birthday.
It is alleged Christensen senior received monthly payments of £11,400, plus VAT, over four years. The total paid was more than £600,000, it is claimed.
Politiken reports Sten Christensen remained as goalkeeper coach with Brondby and says there is no evidence he did any scouting for Chelsea in that period.
Payments or inducements to family members of young players are prohibited by FIFA, UEFA and Premier League regulations.
A Chelsea spokesman said: "We will not comment further on speculation concerning confidential contracts or player related matters."
Sten Christensen told Politiken: "Listen, this is a story you've gotten from some Ukrainian or something.
"I have no comments on this matter whatsoever."
Christensen was a first-team regular last season, but has not played in the Premier League this term.