The family of the first Briton known to have contracted coronavirus "may never know the truth" about his death, his father has said.
His mother Hayley confirmed last week that her son had died at Bangor University where he was a student, describing his death as a "tragic accident".
Following his funeral on Thursday, Mr Reed's father told the Daily Mail that police initially thought his son had hit his head after falling from a chair but a post-mortem examination had proven inconclusive.
Rod Reed said more tests were being done "but it could be up to 12 weeks before we know anything".
He told the Mail: "At first, the police thought he had fallen off a chair in his bedroom (hitting his head on the floor), but the university says not.
"A post-mortem examination has been done because we've got a report from the coroner saying it was inconclusive."
Mr Reed said he had feared his son's death "might be COVID-related" but there had not been a "tell-tale sign" such as a cough.
"We may never know the truth - but we have to try to find it," he told the Mail.
He added: "I don't think it was COVID-related, but you never know."
A North Wales Police spokeswoman told Sky News that the force could not make any further comment as the case had been passed to the coroner.
In a statement released earlier this week, the force said it was called to a student's room at a Bangor University halls of residence shortly after 10pm on 25 October.
"Regrettably, despite the best efforts of friends and paramedics, a 26-year-old student year male student was pronounced dead at the location," a police spokesman said.
The death is not being treated as suspicious, the spokesman added.
Connor Reed's parents and two younger brothers - who live in Australia - had to watch his funeral service at Colwyn Bay Crematorium via a live feed due to coronavirus travel restrictions, the Mail reported.
Describing his COVID-19 symptoms earlier this year, Connor Reed, from Llandudno in North Wales, told Sky News that he felt "really bad" and lost his voice due to the amount he had been coughing.
"It scared me because breathing is a necessity of life, like if you have the flu, you really feel like you're going to die, but you're really not," he said.
"But when your lungs get affected, that's where it scared me.
"And I couldn't take a full breath. And the breaths I did take, it sounded like I was breathing through a bag.
"It was very crackly, and I could only take half breaths. If I walked to the kitchen, for instance, I'd be breathing really shallow and really fast."
He recovered from his illness and a few weeks later doctors realised he had suffered from the virus which would become known as COVID-19.
He also praised China's response to the virus, saying: "China is one of the most efficient countries at getting stuff done. In regard to this outbreak, they've got it done. They had to. They had to take the drastic measures, that many other countries wouldn't have taken."
A Bangor University spokesperson told Sky News: "The university confirms the tragic death of a male student in halls of residence... Our thoughts are with his family and friends at this very sad time.
"Student well-being is a university priority and we are offering support to others in halls and at the university who knew the student."