Gately had been writing a book and planning a new Boyzone album
Boyzone singer Stephen Gately died of natural causes, a post-mortem examination in Spain has established.
An official said he had suffered pulmonary oedema, which is an accumulation of fluid on the lungs.
The 33-year-old star was found dead at his holiday home in Majorca on Saturday. A judge on the island said his body could now be flown home.
X Factor judge Louis Walsh, who created the boy band, said: "We're all in shock. We still cannot believe it."
Walsh, who did not appear on Sunday's X Factor show on ITV out of respect, said he had last seen Gately last week at the Pride Of Britain Awards.
"I was trying to talk him into doing Big Brother and he didn't want to do it. All Stephen wanted to do was sing in the West End."
Family lawyer Gerald Kean said papers had been signed to allow the release of Gately's body, but added it may be two days before it was returned to the Irish Republic, his homeland.
A build up of fluid in the lungs, which can ultimately cause respiratory failure by preventing the lungs from absorbing oxygen properly
Can be caused by direct damage to the lung tissue, or by flaws in the circulatory system
Symptoms may include difficulty breathing, coughing up blood, excessive sweating and anxiety
If the condition develops gradually the need to urinate frequently and swollen ankles can be warning signs
"The family's only wish is to get their son and brother home as soon as possible," he said.
The singer's civil partner Andrew Cowles visited Gately's body to pay his respects on Tuesday evening.
Mr Cowles arrived at the municipal cemetery in Calvia, near Port Andratx, at about 1900 local time (1800 BST), staying for about 15 minutes before leaving without comment.
A court official at the hearing into the cause of death said the pulmonary oedema had been "acute".
She added that once the witness statements and tests had been confirmed then the case would be "closed".
She could not say whether Gately had been taking any drugs or alcohol beforehand but stressed that either way, they had not been the cause of death.
Toxicology results are due later.
A sample of fluid taken during the post-mortem examination will also be sent to a forensic laboratory in Barcelona for further tests to confirm the result.
Andrew Cowles was with Gately the night he died
Amid speculation about the cause of death, including that Gately had been on an eight-hour drinking session, his family has denied he had taken drugs, drunk heavily or killed himself.
Speaking on GMTV on Tuesday, Mr Kean said: "We are absolutely happy that there is no foul play.
"We are not saying he was not drinking but eight hours is not something we accept."
It is believed that Gately died after falling asleep on a sofa after a night out in the city of Palma.
Police said there were "no signs of suspicious circumstances".
It has been widely reported that Gately and Cowles returned to their luxury holiday apartment with another man.
Boyzone members flew out to Majorca to comfort Mr Cowles, but they have returned home now.