Willie McKay, who helped broker Emiliano Sala's ill-fated transfer from Nantes to Cardiff, has angrily denied there was any wrongdoing or corruption in the deal.
Cardiff are gathering information that could lead to them suing him or trying to avoid paying the £15million fee, which they say was artificially inflated by McKay spreading false rumours of other clubs' interest in the player.
They never got to see their record signing play, as the plane carrying Sala to Wales from France crashed into the English Channel on January 21. Days later the plane was salvaged from the water, with the body of the 28-year-old Argentine striker inside.
McKay's admission that he deliberately spread stories about rival clubs' interest — revealed in an email he sent to Sala — is viewed by executives at Cardiff as possible 'price manipulation'.
However McKay refuted claims of corruption, and said he wants a public meeting with press and Cardiff officials in order to clear his name.
He told the Sun: 'We have nothing to hide, the rumours are f***ing c**p, absolutely f***ing c**p. I'm sick of it. I'm shocked people are saying this. I'm waiting for the FA to phone me.
'I want a public meeting with everybody there and you can chair it — Sky, the papers, everybody can come.'
Cardiff are due to make the first payment to Nantes - a little over £5m - on February 27 after a seven-day extension to the initial payment deadline was agreed.
The Air Accident Investigation Branch (AAIB) are due to publish their first report into the crash on Thursday, having spoken to McKay previously.
McKay has been a focus after organising several flights for Sala and Cardiff as the deal progressed, including the Piper Alpha plane that crashed, killing the player.
He said: 'The AAIB know the plane was not owned by me. Why won't the owner come forward? They have probably seen the abuse I am getting.'