Former Sunday Press editor Michael Keane, who died on Saturday morning, has been described by colleagues as a "man of integrity and courage".
Mr Keane, who lived in Sandyford, Co Dublin, was surrounded by his family when he died in hospital.
He had suffered a heart attack about three weeks ago and had remained in ill health.
Mr Keane, who was aged in his 60s, was a journalist with the Irish Press Group working on three newspapers.
In 1972, he became the Northern Editor in Belfast and later the editor of the Sunday Press, a position he held for eight years.
After the group closed, Mr Keane joined Fleishman-Hillard Saunders, an international communications company, where be became a director.
Almost a decade later in 2006, he co-founded communications company Insight Consultants.
Michael Parker, a friend of Mr Keane and the co-founder of Insight Consultants, said he was a fearless journalist who put his life on the line in Northern Ireland when he condemned the IRA's no warning bombing campaign.
“He was a truly old fashioned journalist and a very strong person. He really asked the really hard questions. He mentored so many people in journalism and PR, and took them under his wing,” he said.
“ I’m taken aback today with all the people who have called.”
Mr Parker said the day before he collapsed after a heart attack he was in the office in “fantastic form”.
“He’s a huge loss for us and for me. Michael was brilliant to work with. He was a rock,” he said.
“He was incredibly devoted to his family, a real family man.”
Mr Keane was survived by his wife Jenny and his three adult children Aoife, Simon and Michael Junior.
National Union of Journalists (NUJ) Irish secretary Seamus Dooley said Mr Keane was imaginative, creative and very supportive of his staff.
“He is remembered with great affection among his former colleagues for his kindness and helpful nature, especially towards younger journalists,” he said.
“He was a fearless reporter who upheld the highest editorial standards. He was uncompromising in his coverage of Northern Ireland and was a passionate defender of media freedom.”
Mr Dooley said Mr Keane never lost his love of journalism after changed to a career in PR.
“He remained a ‘Press’ man and retained close friendships with his many Burgh Quay colleagues,” he said.
“In extending sympathy to his family we also extend sympathy to his friends and colleagues, who will miss Michael for his sense of fun, his unfailing good humour and his generosity of spirit.”
The Public Relations Consultants Association (PRCA) has offered its condolences to the family, friends and colleagues of Mr Keane.
Sharon Murphy, PRCA chairman, said Mr Keane was widely regarded and respected in the PR and media industry.
“Michael Keane was a great colleague and a total gentleman. He will be greatly missed by all,” she said.
“It was a privilege to have known him and a pleasure to have served with him on the board of the PRCA. He will be remembered for his tremendous talent, his huge contribution to the PR industry and the media, and his warmth and decency. May he rest in peace.”
