The developer's testimony to the Mahon Tribunal included allegations that attempts to build a shopping centre in Co Dublin were met with demands for payments from politicians.
At his funeral in a remote parish church in Co Donegal yesterday, his son Thomas spoke of a "remarkable man".
Speaking before the Mass at St Michael's Church in Urris, on the Inishowen peninsula where his mother Vera is from, Thomas Gilmartin Jnr said his father (left) had only left Ireland after being denied a job with the civil service in Dublin because he didn't have the right connections.
"Unfortunately as is very common in the Ireland of the 1940s and 1950s, opportunities to make the most of his God-given talents were few and far between," said Thomas.
Mr Gilmartin said his father had been forced to emigrate instead, and found himself in Luton, England, working with and giving jobs to many people from home.
He had been extremely successful and had returned to Ireland in the 1980s hoping to create jobs.
"Unfortunately my father was let down by people for whom moral scruples, or the type my father lived by, was seen as a weakness.
Mr Gilmartin was laid to rest in the graveyard overlooking Tullagh Bay, and less than half a mile from the cottage where his wife was born and where the couple and their family spent summer holidays for a half a century.