Tom Gilmartin, who was in his late 70s, died in Cork University Hospital (CUH) after bravely battling a long term illness.
Originally from Sligo, Mr Gilmartin built a hugely successful engineering business in Luton in the UK.
The decline of the UK car industry led him to move into construction and development in the 1980s in the UK, Northern Ireland and the Republic.
However, his experiences of planning in Dublin, particularly in relation to a proposed shopping centre, was one of the primary causes for the establishment of the Mahon planning tribunal in Dublin Castle.
Mr Gilmartin agreed to co-operate with the tribunal after he was left incensed about comments made about him by former Government Minister and EU Commissioner, Padraig Flynn, during a 'Late Late Show' appearance on RTE.
Many of Mr Gilmartin's allegations involved the late Liam Lawlor and Cork-based property developer Owen O'Callaghan.
Following the publication of the hard-hitting Mahon tribunal report, the Gilmartin family claimed it was a total vindication of Tom Gilmartin's position.
Mr Gilmartin retired from the UK to live in Cork, initially residing in the Lough before moving to a property off the Model Farm Road in Bishopstown.
He had suffered ill health over recent years but had repeatedly expressed his annoyance over much of the media coverage of the planning tribunal.
Mr Gilmartin left Sligo in 1957, against his father’s wishes, to pursue a career in the UK.