Prime Minister Kevin Rudd has offered an unreserved apology on behalf of the government for the electrocution death of three young men killed installing ceiling insulation as part of the rushed government program in 2009 and 2010.

Describing the deaths of Matthew James Fuller, Reuben Kelly Barnes and Mitchell Scott Sweeney as an "unspeakable tragedy", he said in Jakarta: "As the Prime Minister of this country I am deeply sorry for what has occurred and, of course, I apologise for these deaths, given that it was a government program."

The parents of Mr Fuller, a 26-year-old electrician, had earlier called for an apology from Mr Rudd, who was Prime Minister at the time of their son’s death. They told the ABC that Mr Rudd "couldn’t remember our names and has never apologised to our face".

The Queensland Coroner handed down the findings into the deaths on Thursday, and criticised the federal and Queensland governments over electrocution of the three young Queenslanders in 2009 and 2010.

The directors and supervisors of ceiling insulation businesses that employed the young men could also face Workplace Safety charges.

Mr Barnes, 16, Mr Fuller, and Mr Sweeney 22, were electrocuted while installing foil insulation in Queensland homes as part of the federal government’s $2.45 billion Home Insulation Program that was designed to stimulate the economy during the global financial crisis

Mr Rudd said he accepted the criticisms of the government by the Queensland coroner, saying: "Let’s not beat around the bush - this was a government program."

However, the opposition said on Friday that Mr Rudd's apology was insufficient and vowed to pursue the Prime Minister over the issue.

Shadow treasurer Joe Hockey said on Friday that Mr Rudd was warned in writing about the dangers of the program on 10 occasions and he had not released those letters.

"Four of those letters came from Peter Garrett who has not only resigned from ministry but refuses to work with Kevin Rudd, resigning from parliament,'' Mr Hockey told the Seven Network.''

In his findings, State Coroner Michael Barnes said the federal government had not adequately assessed the risks for the program - noting that speed was a major contributor to this factor.

"The scoping of the risks likely to be generated and the safeguards that would contain them were miscalculated and inadequate," Mr Barnes said.

"Undoubtedly, a major contributor to the failure ... was the speed with which the program was conceived, designed and implemented."  

The Coronor noted that because a major focus of the program was to stimulate the economy, it needed to be rolled out much more quickly than a two year time frame nominated by experts, "but not at the cost of human life".

"It is reasonable to conclude the dangers should have been foreseen and mitigated before three people died in Queensland and another in New South Wales."

While the Coroner noted that work place safety regulation was primarily a state government responsibility, he also said it was "reasonable to expect" that when the federal government injected billions of dollars into the economy via a program designed to create employment for unskilled or unemployed workers, "it would have regard to the possible safety implications".

Deputy Opposition Leader Julie Bishop seized on the report on Thursday.

"The Queensland Coroner's report is a scathing, damning indictment of the former Rudd government," she told reporters in Darwin.

Ms Bishop said Mr Rudd needed to explain how warning were ignored and risks were not taken into account.

She said that Mr Rudd must release the letters containing warnings that were sent to his government.

Last week, before the Coroner's findings were handed down, Opposition Leader Tony Abbott wrote to Mr Rudd, asking him to release all correspondence he received about the home insulation scheme when he was first prime minister.

Specifically, Mr Abbott requested four letters from former environment minister Peter Garrett in 2009 and four ''warnings'' provided by the Department of the Prime Minister and Cabinet in 2009 and 2010.

''As you would know, the implementation of the Home Insulation Program was a low-point in your previous administration,'' Mr Abbott said.

''I trust that you will honour this request in the interests of openness and transparency.''

Attorney-General Mark Dreyfus said the deaths were a ''deep tragedy'' and repeated Mr Rudd's apology.

On Friday, he told ABC Radio that the federal government had done everything it could to assist the coronial inquiry and ensure the families had legal advice.

But he said he would not comment on whether there should be compensation.

The Coroner referred Mr Barnes’ bosses Christopher and Richard Jackson, who were executive directors for Arrow Property Management, for potential breaches of the Electrical Safety Act.

Christopher Jackson will also be investigated for perjury for allegedly giving false evidence during the inquest.

Mr Fuller’s supervisor Ben McKay will be investigated to determine if he breached workplace health and safety laws by leaving the untrained worker unattended.

The Coroner condemned the lack of training the companies gave their employees and said the two Queensland workplace safety organisations reacted very slowly despite the obvious risks to untrained installers working in roof cavities.

"The dangers should have been foreseen before three people died in Queensland and a fourth in New South Wales," he said.

Mr Barnes was especially critical of subcontractors using metal staples instead of plastic staples, with some suggestions given that installers found metal staples faster and easier to use.

Mr Barnes recommended the Queensland government make the installation of electrical safety switches compulsory in all Queensland homes "as a matter of urgency".

He also highlighted that there had still not been an electrical safety review of ceiling insulation work in Queensland.

He ordered that Safe Work Queensland conduct an urgent review.

Mr Barnes also ordered an immediate large scale public relations campaign to warn householders of the electrical dangers inside roof cavities.

Outside the court, a lawyer for Mr Fuller's family said his clients were pleased with the inquest's findings.

"The findings do justify their persistence in wanting this inquest to take place," the representative said.

"The findings do show some level of blame, not just to the employer, but also to those people in state and federal governments."

Peter Koutsoukis, from Morris Blackburn lawyers, said Mr Sweeney's family welcomed the findings from the inquest.

In particular they approved of Mr Barnes' conclusion that employers could not distance themselves from responsibility for care because an employee was a contractor.

Mr Koutsoukis said that was important for Mr Sweeney's family, which was suing Titan Insulations for almost $325,000 for its loss.

"The coroner found that the younger a person is, the more the responsibility shifts to an employer to ensure their safety at work, " Mr Koutsoukis said.

"And it is not not negated by any assertion that the person is a subcontractor rather than a straight employee," he said.

Mr Koutsoukis said the family welcomed Mr Barnes' finding that Titan had not supervised Mitchell's workplace and that "little or nothing" was done to assist installers avoid putting metal staples through live power cables.

Meanwhile, CEO of Master Electricians Australia Malcolm Richards said the home insulation scheme was rushed from the beginning.

"It was too fast, without adequate safeguards and it encouraged people to cut corners and to lower safety standards in an attempt to gain quick money, " he said.

He said he personally raised safety concerns with federal government ministers at the time.

"I met personally with Peter Garrett a number of times personally to impact on him the importance of improving the safety in the scheme," he said.

Mr Richards described the inquest as "touching and very unfortunate for all the families involved".