Mystery still surrounds his death, with friends claiming the 61-year-old had complained of feeling particularly unwell in recent times.
Known for his fiery temperament and audacious skill with a cue, the two-time world champion was credited with revolutionising the sport’s popularity.
And as the world of snooker mourned the passing of one of its most charismatic figures, plans were being drawn up for Higgins’ funeral, with thousands of fans expected to pay their final respects.
Some £10,000 which had been raised to help Higgins receive medical treatment prior to his death will now be used to give him “a great send-off”, one of his closest friends said.
Will Robinson, who also worked as Higgins’ personal assistant, said sport had lost one of its true greats.
“He was a genius, we’ve lost one of the great sportsmen,” he told the Belfast Telegraph.
“You think of great sportsmen from Ireland and you think George Best and Alex Higgins.
“It’s a very sad day for sport and for Northern Ireland.”
Mr Robinson said money from an auction and fundraising dinner will be used to give his friend a lavish funeral.
“There's probably about £10,000 in total when we get everything in. Now that's going to pay for a great send-off,” he added.
Funeral details have not been finalised, as fellow snooker star Jimmy White, who was close to Higgins, is in Thailand and wants to travel back to attend. It is understood Higgins’ family have agreed to this.
There has been unconfirmed speculation that Higgins had asked to be buried in Cork, in a burial plot beside his late friend Oliver Reed.
Meanwhile, a book of condolence will be opened at Belfast City Hall this morning for fans to pay their own respects.
Higgins' body was discovered after concerned friends broke into his flat having failed to contact him by phone.
It is not known how long he had been dead inside the apartment and there are fears he may have lain dead in bed for a number of days.
By the time medics arrived, fans had gathered outside the flat to say a final farewell.
As the ambulance drove away, one man shouted: “He was our champion”.
Yesterday, locals gathered inside the Royal Bar, opposite his home, to raise a glass by the empty seat where Higgins spent so many nights.
One friend, Noel Cairns, said he would be remembered as the greatest snooker player that ever lived.
Higgins’ daughter Lauren, who made peace with her dad when he was diagnosed with throat cancer, was said to be “inconsolable”.
She and her brother, Jordan, had been estranged from Higgins for years after their mother, Lynn, divorced him.
His devastated sisters Jean and Ann said they were too upset to speak about their brother’s death.
Former World Champion Dennis Taylor led the tributes to the man who infamously threatened to have him shot. “I don't think you'll ever, ever see another player in the game of snooker like the great Alex Higgins,” he said.
Higgins’ final days, spent in a simple bedsit in south Belfast, were a humble end to a life lived out in the spotlight.
Aged just 11, Higgins had discovered the game that would dominate his life.
He won the All-Ireland and Northern Ireland amateur snooker championships in 1968 and, after turning professional, became the youngest world championship winner at his first attempt, beating John Spencer in 1972.
Despite his success, which included another world title in 1982, away from the snooker hall Higgins’ life was a chaotic whirlwind of drink, womanising, fights, illness and debt.
He earned millions in the years when snooker was a British national obsession, but blew it all in a long and turbulent descent into homelessness and drink. He wasted his £4m fortune, while two marriages ended in divorce.
Before his death, Higgins had shrunk to just six stone and was living off benefits.
His body had been savaged by radiotherapy and years of alcohol abuse, while he had once experimented with drugs and smoked up to 80 cigarettes a day.
Sean Boru, who ghosted Higgins' autobiography, said: “The problem with Alex was that he knew he was a great talent but he didn't quite know how to work it. He never really fully got the gist of the fame game.”