Lise Theriault said a judge granted a request by the trio on Friday to have more flexible detention conditions, including the possibility they no longer be obliged to wear handcuffs.
Theriault, who is also public security minister, told a news conference in Nicolet, Que., she doesn't know why the judge agreed to the request.
"On Friday, the prisoners petitioned a judge to have their measures of confinement loosened and the judge agreed," she said.
Later, she told reporters in Quebec City the decision was "questionable" given the sequence of events that followed.
The spectacular escape dominated question period in the national assembly on Monday, with Theriault peppered on the subject for more than 30 minutes.
She was asked several times by interim Parti Quebecois leader Stephane Bedard why the government did not appeal the judge's decision.
Theriault's repeated response was that everything would be made public "at the opportune moment."
At one point, she pointed out that the inmates' request to have their security restrictions eased was first made on March 21 when the PQ government was in power.
The public security minister also said a plan had been put in place in Quebec's detention centres to make sure it wouldn't happen again —although she didn't provide any details.
Yves Denis, Denis Lefebvre and Serge Pomerleau escaped from the Orsainville Detention Centre in suburban Quebec City on Saturday evening when a chopper landed in a courtyard, scooped them up and quickly took off.
Police say the three men were originally arrested on drug-trafficking and gangsterism charges in 2010.
The Quebec provincial police website also says Denis, 35, is facing first-degree murder charges, while Lefebvre, 53 and Pomerleau, 49, are facing charges of murder and conspiracy to commit murder.
Premier Philippe Couillard echoed his deputy premier, saying the No. 1 priority is to capture the fugitives.
"First and foremost today, we must be sure that those individuals will be captured (and) brought back to jail so they cannot harm anyone," he said in Montreal.
Couillard said two important areas need to be studied.
"Here I see elements like the levels of security inside the jail, and also how air traffic is monitored above our security institutions," Couillard told reporters at an economic forum.
Theriault said the incident will lead to renewed discussions with Ottawa about how to control air space over detention centres in Quebec.
Federal Transport Minister Lisa Raitt said in Ottawa that she will investigate just what conversations have taken place in the past because she has not been contacted about the issue before.
She said she has now asked her officials to look into the "state of play" of the air space over the prison.
"I understand that below 2,500 feet that it's not restricted air space," Raitt said. "Above 2,500 feet it's the provincial civil aviation authority who has that air space."
She said provincial officials can approach Transport Canada to regulate the air space and will have to follow the appropriate process to do it.
Theriault said she would meet with officials in her department to discuss additional security measures, notably the installation of metal wiring above detention centres to prevent helicopters from landing.
There were reports that steel wire aimed at preventing such escapes had been bought but not installed at detention centres.
"We're going to look into that, to see why it wasn't installed," she said. "I just want to remind you that I've only been on the job for six weeks."
Theriault defended police as they continued their search for the convicts.
"It's not easy," she said. "Quebec is big. There are a lot of places where people can hide."
Saturday's helicopter escape had similarities to another bold jailbreak in Quebec.
A helicopter pilot was forced at gunpoint to fly to a prison in St-Jerome in March 2013.
Two convicts climbed a rope ladder into the hovering helicopter and fled.
The two escapees and the two men accused of hijacking the chopper were picked up by police in Mont-Tremblant, about 85 kilometres away, within a few hours of the escape.
— With files from Alexandre Robillard in Quebec City, Julien Arsenault in Montreal and Joan Bryden in Ottawa
Editor's note: A previous version of this story had an image that incorrectly identified the prisoners involved. The image has been updated to correctly identify them.