GRAVENHURST, Ont. -- A drunk driver who killed three young children and their grandfather in a crash north of Toronto continues to minimize his problems with alcohol and must address the issue before he can be released into the community, a parole board panel ruled Wednesday.

By underestimating his misuse of alcohol, Marco Muzzo is sabotaging the progress he could be making while behind bars, members of the Parole Board of Canada said in denying the 32-year-old both day and full parole.

"We don't question your remorse," board member Kevin Corcoran said in a hearing at the Beaver Creek prison in Gravenhurst, Ont. "It's obvious that this is a very difficult thing for you to deal with."

However, he said, "we have to be mindful that your actions caused the deaths of four people."

Muzzo, who was sentenced to 10 years in prison in 2016 after a guilty plea in the crash, can appeal the ruling in the next two months or reapply for parole in a year.

During an emotional hearing that spanned roughly three hours, he was pressed on his drinking habits prior to the September 2015 collision and his record of driving infractions, many of them for speeding.

Muzzo, who showed little emotion through most of the questioning, was confronted with a 2012 incident that saw him charged with public intoxication after he threatened a bouncer at a strip club and tried to kick out the windows of a police cruiser after his arrest.

The incident was not mentioned during his trial and the panel said it had only recently come to the attention of Muzzo's case management team, noting it suggested a lack of transparency on his part.

Muzzo insisted it was an isolated incident, that he seldom drank and only to excess on birthdays and other festive occasions. Corcoran disagreed.

"This speaks to a history," the parole board member said.

The panel also said it appeared police officers had reduced several of Muzzo's speeding tickets, meaning he would never have received demerit points or lost his licence. As a result, the panel said, Muzzo never faced consequences that might have changed his behaviour or attitude toward driving.

Muzzo pleaded guilty to four counts of impaired driving causing death and two counts of impaired driving causing bodily harm in the crash.

The collision in Vaughan, Ont., claimed the lives of nine-year-old Daniel Neville-Lake, his five-year-old brother Harrison, their two-year-old sister Milly and the children's 65-year-old grandfather, Gary Neville. The children's grandmother and great-grandmother were also seriously injured.

The crash set off a wave of public grief that led to several candlelight vigils to honour the victims. It also sparked debate on the legal penalties for drunk driving, with some advocacy groups calling for tougher sentences.

The parole board panel said it received numerous letters both against and in favour of granting Muzzo some form of release, as well as a petition with the names of thousands of people opposed.

The mother of the children Muzzo killed told the hearing that his expressions of remorse rung hollow as he had sought parole at the first opportunity.

"I don't and won't get the chance for parole from this life sentence of misery and despair," said Jennifer Neville-Lake.

She described coming home to an empty house every day and straining to hear the shuffle of her children's feet or the rustling of their bodies tossing and turning in bed. At the same time, she said, the sound of other children laughing can trigger a wave of grief.

Muzzo appeared emotional during her statement and seemed to wipe away tears on at least one occasion.

After the hearing, Neville-Lake said she took no comfort in the outcome, even if it was the one she sought.

"It's not a victory because it doesn't change a single thing for me," she said, adding that nothing can bring her family back to life.

The crash took place after Muzzo had returned from his bachelor party in Florida on a private plane and picked up his car at Pearson International Airport. He was speeding and drove through a stop sign, T-boning the minivan carrying the Neville-Lake family, his court case heard.

Muzzo told the parole hearing that he had been drinking until 3 a.m. during his bachelor party and then had up to four drinks on the flight back, but still felt he could drive.

"I should have known better but I took a chance," he said.

Muzzo struggled to say that he had been driving impaired and eventually told the panel he thought it would take eight or nine drinks to meet that definition.

When asked if he had driven drunk before, Muzzo said he had driven after having some drinks in the past but had never done so while "wasted."

A parole officer said Muzzo did not meet the criteria for mandatory substance abuse treatment, but the panel asked why he had not voluntarily sought help, noting that programs ranging from 60 days to six months had been suggested.

Muzzo said he tried Alcoholics Anonymous but found it wasn't for him.

"I firmly believe I'm not an addict," he said. "I'm scared of it now, I'll never touch it."

Muzzo also said he still vividly remembers the screams from the crash.

"It's something I can't forget," he said.

The Muzzo family, one of Canada's wealthiest, owns the drywall company Marel Contractors.