The family of a man who died after a possible homophobic assault in Londonderry last year have appealed for information about his final movements, saying they “can’t settle” until they know more about his last days.

Terry McCartney, a 42-year-old gay rights campaigner, was found dead in his flat in Londonderry on 5 February 2013.

At 2.50 am, on the morning of his death, he had been in an altercation with a group of men at Shipquay Gate, and was punched to the ground.

After a post mortem police ruled that his death was not suspicious.

His family launched an appeal for more information this week, particularly hoping to contact a person who was at Shipquay Gate on the night and reportedly helped Mr McCartney after he was hit.

Mr McCartney had been badly beaten in 2004 in a homophobic attack, and his family say he “suffered all his life” for his sexuality. As the reasons for the altercation in 2012 are unknown, his family have questioned whether it may have been another homophobic attack.

“So many rumours have been doing the rounds about Terry’s death,” said his mother, Margaret to the BBC. “I want people to know that his death was totally unrelated to other incidents that took place in the city that weekend. Also, I think it’s important to stress that the assault had nothing to do with his death. All this speculation doesn’t help.”

She added: “I need to know what Terry was doing in the hours before he died. Until I know where he was, what he was doing and who he was with, I can’t settle.

“All I have at the minute are questions; I need answers. Any scrap of information – however unimportant it might seem – could be helpful.”

McCartney’s sister, Michelle, said: ”The police know as much as we do. We just want to find out what happened to Terry leading up to his death, or leading up to the assault.

“He was hit once and went to the ground. A man picked Terry up. If he had a bit of information, it might only be a wee thing but it might help us find out what happened to Terry.”

The death was a severe blow to the McCartney family, which lost another son to suicide over a decade ago.

“I thought it could never happen again and it has,” said Michelle. “I wouldn’t wish this on anybody. I just wish we could get some answers.”