Property developer Sean Dunne is trying to set aside an Irish court order declaring him bankrupt.
The US-based businessman was adjudicated a bankrupt last July over a €161m debt to Ulster Bank which arose from property loans.
The High Court has heard he has not been domiciled in Ireland since 2007.
Mr Dunne, who claims to have debts of $1bn and assets of €55m, had filed for bankruptcy in the US.