High Court proceedings have been issued on behalf of Dublin businessman Harry Crosbie against the National Asset Management Agency (Nama).
The proceedings claim that Nama is in breach of a solemn agreement it entered into with Mr Crosbie and which was committed into writing in August 2012.
The proceedings demand that Nama cease pursuit of any outstanding debt against Mr Crosbie.
If successful, the legal action would require Nama to cease pursuing Mr Crosbie over his alleged debts, to remove their receiver from the Bord Gáis Energy Theatre, and to compensate Mr Crosbie for alleged leaks made by the agency of personal information regarding his financial affairs.
Nama claims Mr Crosbie failed to disclose substantial assets to the agency and paid his wife €1.4 million just prior to it taking over his loans in 2010.
The claims were made in the Commercial Court earlier this month by the agency, which is seeking a €77 million judgment against Mr Crosbie.
It said it took action against the businessman because he failed to disclose substantial assets, including three apartments in the south of France, when asked to provide details of all assets held by himself and his family,.
Mr Crosbie, who is being represented by Former minister for justice and attorney general Michael McDowell, has disputed the claims.