Patrick Rocca, 41, was discovered with a single gunshot wound to the head. The Irish Gardai said they were satisfied that nobody else was involved.
Mr Rocca had a fortune which was put at €500m (£462.9m) in 2007 and he is thought to have completed 20 property deals in the UK worth more than €300m through his company, Accorp Properties.
According to reports in the Irish press, the father-of-three may have lost large sums of money in Anglo Irish – the Irish bank that collapsed into full nationalisation last Friday.
Mr Rocca was a member of the prominent family that once owned Rocca Tiles. They include his sister, former Miss Ireland, Michelle Rocca, who is the partner of Irish musician Van Morrison.
