Gary was found dead in his flat in Liverpool after being taken ill some weeks ago and had been undergoing tests.
Originally from Belfast, he had been staying there with family recently but had returned to England to attend an Iron Maiden concert with a friend.
Most recently he had been employed as a sub-editor at the Chelsea Football Club magazine.
Gary’s death comes almost 17 years after his brother Ryan was killed in a car crash in South Belfast at the age of 19.
Speaking to the Irish News on Wednesday, their brother Darren described Gary as someone who “loved life” and was “always thinking of others”.
He added: “He loved writing and he was a keen golfer and musician. He played the guitar. He used to do a few gigs when he lived in Belfast but in Liverpool it was a hobby.”
Darren told the News that Gary became ill around a month ago but after undergoing treatment had started to “pick up a bit” and decided to travel to Liverpool with his friend for the weekend.
He added: “The guy with him said he had a great night on Saturday night. It is just unbelievable.
“We lost my younger brother 17 years ago. Ryan died in different circumstances. It’s nothing you ever expect to go through, especially for my mum and dad. It has been just devastating.”