Father of four Seamus Doherty, 67, had suffered a number of injuries in an attack at his home in the townland of Drumacanoo.
But a post mortem also revealed he had been strangled.
Gardai and ambulance crews were called to the scene at 1.40am on Sunday morning. Mr Doherty was pronounced dead at the scene.
Donegaldaily has learned that Gardai detected a number of initial injuries, but further injuries were discovered by State Pathologist Dr Marie Cassidy during a post mortem on Tuesday afternoon at Letterkenny General Hospital.
A number of people have been interviewed as witnesses about the crime.
However we understand Gardai have not, as yet, obtained an explanation for how Mr Doherty received any of his injuries.
Gardai will not reveal the extent of his injuries but Supt Eugene McGovern told donegaldaily.com at Letterkenny Garda Station yesterday that further inquiries are being made.
He refused to reveal what the injuries were.
Meanwhile Mr Doherty’s family are said to be still in shock at his death.
A niece posted on donegaldaily’s Facebook page: “A well loved man. RIP uncle Seamus.”
Mr Doherty’s remains are expected to be released to his family later today.