The PSNI said a post mortem examination on the body of Herbie Porsche will take place today.
Mr Porsche, 60, was working on a boat when he took ill at Crawfords Marina, Carrybridge, Co. Fermanagh, on Wednesday evening.
The German native, who lived outside Inver, Co. Donegal, hit the headlines after persuading Dragon’s Den judges to invest in a toilet pipe cover to improve the appearance behind toilets.
He became such a star locally from his Dragon’s Den appearance that he was the 2010 Grand marshall in the St Patrick’s Day parade in Ardara.
It is believed Mr Porsche suffered a heart attack and fell into the water in Lough Erne from the boat.