The High Court in London has been told the millionaire Barclay brothers would stop at nothing to undermine the financial position of Belfast born developer Paddy McKillen.
Mr McKillen is suing David and Frederick Barclay, owners of Telegraph Newspapers and the Ritz Hotel, in a dispute over three London hotels - Claridges, The Connaught and the Berkley Hotel.
Mr McKillen is attempting to stop publication of further details of his financial position, which his legal team says will allow the Barclay twins to destabilise the developer in relation to other assets.
Counsel for Mr McKillen, Philip Marshall, QC, said there was evidence that the Barclay brothers' representatives had been in contact with lenders who held security over Mr McKillen's shares in Coroin, the company which controls the three hotels at the centre of the legal dispute.
The court heard that representatives of the Barclay brothers had contacted Bank of Scotland (Ireland) hoping to encourage enforcement of Mr McKillen's loans with the bank.
Contact had also been made with IBRC, formerly Anglo Irish Bank, in an attempt to buy Mr McKillen's debt.
Mr Marshall said when that failed the Barclays’ representatives had contacted the Department of Finance in Dublin to point out what was described as "the dangers to the Irish taxpayer of any delay by the IBRC".
Rejecting arguments in favour of confidentiality, counsel for the Barclay brothers told Mr Justice David Richards that Mr McKillen was a well-known businessman and had well-publicised business dealings which he now sought to conceal.
Kenneth McClean, QC, said there was no reason why those business dealings should not be subjected to the full glare of publicity in court.
"It is not for Mr McKillen to marginalise the relevance of this material, " Mr McClean said.
"It is not peripheral and while it remains part of Mr McKillen's case the Barclay brothers are entitled not to have one hand tied behind their back. There is material which is relevant to the case and should have been made available in any event."
Referring to contacts by representatives of the Barclay brothers with Paddy McKillen's lenders, Mr McClean said it was perfectly lawful for the Barclays to approach Anglo Irish Bank to attempt to secure Mr McKIllen's debt, although Mr McKillen may have not liked it.
Legal argument over the issue of the confidentiality of Mr McKillen's financial status will continue tomorrow.