The former chairman of Cardiff City football club, Sam Hammam, has been named as the man behind a bank demanding repayment of £31m in loans.
Sam Hammam was succeeded by Peter Ridsdale as Cardiff chairman
The club spent the day in the High Court after legal action brought by Swiss based financiers.
The Langston Corporation claims the club has failed to make a payment on the loan made in 2004.
However, for the first time, the club's barrister named Mr Hammam as the man behind Langston.
The bankers want the court to make a summary judgement in the case, which would see Cardiff City facing a bill to repay £24m immediately of the £31m that is outstanding.
But the club claims the loan is not repayable until 2016 and it could face an uncertain future if it loses the case.
Peter Ridsdale fears for the club's future if it loses the case
At the start of the two day hearing, Langston's counsel, Michael Driscoll QC said: "It is common ground that the claimant loaned £24m to the club in 2004 and is yet to be repaid.
"The club says that nothing is to be repaid at this time, and the question is whether there is enough in what the club says to justify this case going to trial.
"The claimant says that there is nothing in what the club has said."
Cardiff claims a variation to the loan agreement in 2006 means the loan is not repayable for another eight years.
The judge, Mr Justice Michael Briggs, must decide whether he is able to issue a summary judgement ordering the immediate repayment of the £24m, or if the case should go to a full trial.
The judge is expected to reserve his decision before ruling in writing at a later date.
The Championship club is due to play Barnsley at Wembley stadium in April as FA Cup semi-finalists, but its chairman Peter Ridsdale, who succeeded Mr Hammam in the post, has said administration would be a realistic scenario should it fail to win the case.
This could result in an automatic points deduction and damage their hopes of building a new stadium on the outskirts of Cardiff.
Speaking before the hearing, Mr Ridsdale said: "If we were to lose we would go straight into administration - it's a straightforward situation.
"The club's Championship status would be determined by the amount of points we collect come the end of the season, minus 10.
"In terms of the stadium, it would depend who buys the football club and whether they prove to be an acceptable partner for the council and whether they have got enough money to finish the stadium off, which would probably be about £20m."