• Football Leaks says father was paid £11,400 plus VAT a month • Chelsea say they ‘do not comment on confidential contracts’

Chelsea are facing further allegations that they breached Fifa and Premier League rules by making illegal payments to the father of Andreas Christensen in order to sign the Denmark defender.

According to documents obtained by Football Leaks, and published on Thursday by the Danish newspaper Politiken, Chelsea recruited Sten Christensen as a scout on the day they signed Andreas from Brondby six years ago.

According to copies of Chelsea’s consultancy agreements, published by Politiken, Christensen Sr began working for the club on the same day as his son – 1 July 2012 – and was paid £11,400 per month plus VAT for four years, an outlay that totalled £656,640.

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This was while Christensen Sr was being employed by Brondby as the Danish club’s goalkeeping coach. Politiken claims there is no evidence that Christensen did any scouting for the club in that time. Chelsea, one of five Premier League clubs being investigated by Fifa over possible violations of rules on the signing of foreign players under the age of 18, which carry the threat of a transfer ban, have declined to comment on the specifics of Sten Christensen’s role or the allegations that the payments to him would have constituted a breach of Premier League rules.

Payments or inducements to the families of young players are prohibited, with Everton and Liverpool having been fined by the Premier League and banned from signing under-18 players in recent years. The governing body has expressed a willingness to investigate if it receives “any substantiated material that indicates our rules may have been violated”.

Politiken contacted Sten Christensen, who responded: “It sounds like a story you have got from someone in Ukraine or something like that. I have no comment whatsoever. You’ll have to ask Chelsea about that.” When pushed, he added: “That is not something I want to discuss. That’s the way it is. If you want to use information hacked from Chelsea then go ahead.”

A Chelsea statement added: “We do not comment on speculation about confidential contracts or player-related cases.”

The documents released by Football Leaks and published by Politiken suggest Manchester City, another of the quintet of English top-flight clubs under investigation by Fifa, were apparently prepared to breach Premier League rules to sign the highly rated Christensen, who attracted offers from 28 clubs before signing for Chelsea.

A City document headlined “Financial Summary of Youth Acquisitions” and dated 6 January 2012 includes Christensen with a valuation of £430,000 and an additional note: “£230,000 to family.” The document adds: “We have information that Chelsea has offered to accommodate these numbers.”

Manchester City have repeatedly said they “will not be providing any comment on out of context materials purported to have been hacked or stolen from City Football Group and Manchester City personnel and associated people”.