Cardiff City chairman Peter Ridsdale has accused former owner Sam Hammam of trying to destabilise the club.
Peter Ridsdale offered to resign as Cardiff chairman last week
Last month Cardiff were threatened with court action over a £24m loan from financial backers Langston.
Ridsdale said he still does not know who Langston are and that all contact with them has been through Hammam.
"I think Sam is trying to create a shadow over the club, but what I think he needs to do is to be as open about it," Ridsdale told BBC Wales Sport.
"All Sam has to do is pick up the phone and have a conversation.
"I think the sad thing about it is there's so much progress being made, and if it is Sam, pick up the phone and talk.
"If it's not Sam then someone should have the guts to stick their heads above the parapet and say who they are."
I am in it as long as it takes to do the job as long as I've got the support of the supporters and the shareholders
Cardiff City chairman Peter Ridsdale
When Ridsdale arrived at Ninian Park in 2005 after being head-hunted by Hammam, Cardiff were losing £9m a year and had debts of £30m with the new stadium project looking in tatters.
Hammam left the club last October so that new investors could come in and sold his stake two months later, leaving former Leeds chairman Ridsdale to take control.
But last month Cardiff were threatened with court action over a £24m loan from Cardiff backers Langston, taken out by Hammam.
Langston's solicitors, Hextalls, claim the club's board was mismanaging its finances and misleading supporters, and said the money had to be paid immediately.
But Ridsdale has insisted the loan is not due to be paid back until 2016 and has pleaded on Hammam to help them settle the dispute.
"Sam signed an irrevocable at Christmas to sell his shares because it was the only thing to save the club and he was adamant at the time that he cared about the future of the club," said Ridsdale.
"If it was the case then, fine. If it's the case still today he can help us solve the problem because he can sit down and talk to us and tell us who Langston are.
"We do know he is in contact with a number of people and he does appear to be extremely well informed about the current situation about the legal case. You can draw your own conclusions from that."
Ridsdale revealed earlier this week that he had offered his resignation to the club's board, which was rejected, after he received text messages calling for the return of Hammam.
He described the messages as "very personal attacks".
"I feel slightly embarrassed that it became public in the first place," he said. "But the supporters were magnificent on Saturday in light of some of the Press comments."
And Ridsdale insisted: "I am in it as long as it takes to do the job as long as I've got the support of the supporters and the shareholders.
"But this isn't about me, it's about Cardiff City Football Club."