Derby County owe £15m to MSD Holdings, it has been confirmed by the US investment group.
The detail is included within MSD's annual financial statements.
MSD has become a significant presence in English football, lending money to a number of Premier League and Championship clubs, including Burnley and Derby.
The Rams went into administration last month amid spiralling losses, triggering a 12-point deduction.
In a statement, MSD says it has "loan investments in four UK football clubs" at an amortised cost of $208m (£153.47m) and that they "believe the company's exposure to new opportunities will grow over the upcoming years".
It has become common practice in recent years for Premier League clubs to borrow TV money in advance of central distribution to provide more flexibility in the transfer market.
As a second-tier club, Derby have no access to those funds.
And MSD confirmed that "one of the underlying borrowers associated with a £15m loan entered administration".
However, the statement added that "the company holds collateral well in excess of the loan's outstanding principal and interest".
This is understood to be against Derby's Pride Park Stadium.
In addition to this sum, Derby are known to owe HMRC in excess of £20m, plus significant sums to other football creditors, including former manager Phillip Cocu, ex-captain Richard Keogh, and Arsenal, who have deferred the remaining £8m they are owed for Polish defender Krystian Bielik.
Club sponsor 32Red has offered to advance payments for the remainder of the season to help Derby in the short-term but the administrators have said they will need to borrow money at some point.
Listen to the latest BBC Radio Derby podcast about the situation at Pride Park here.