The royal commission into the former Rudd government’s bungled “pink batts” scheme will probe the actions of the government and public servants involved.

Kevin and Christine Fuller are about to spend their fifth Christmas without their son, Matthew, but take some comfort in knowing they’re a step closer to finding out why he died installing home insulation.

A $25 million royal commission into the Rudd government’s bungled “pink batts” scheme to establish “what really went wrong” opened on Monday.

Mr Fuller is hopeful the commission will uncover the truth about the program that’s been blamed for the death of his 25-year-old son and fellow insulation installers Rueben Barnes, Mitchell Sweeney and Marcus Wilson.

“What we’ve always wanted is the truth, the whole truth to come out,” Mr Fuller told reporters on Monday.

“(And for) changes to be made so no one else goes through what we’ve been through.”

Commissioner Ian Hangar QC says he will examine whether the deaths of the four men between October 2009 and February 2010 were avoidable had there been a different approach to workplace health and safety risks.

The $2.8 billion program launched by Kevin Rudd in early 2009 to inject money into the economy has also been linked to at least one serious injury and hundreds of fires.

The royal commission will investigate whether the government sought or received advice about the program and how it responded.

It will also investigate the actions of the government and the public servants involved.

Mr Fuller says both state and federal public servants still had a lot to answer for as previous inquiries had only established that employers “did things wrong”.

Lawyer Bill Potts says he would like to cross-examine Mr Rudd and other ministers involved in the program on behalf of his client Murray Barnes, the father of Rueben.

However, Mr Potts says the commission mustn’t turn into a political witch hunt.

“What we want to know is whether there were warnings, and if there were warnings why weren’t they heeded?” he told reporters.

Mr Potts said there was little to protect Rueben, 16, from being electrocuted while installing home insulation at Rockhampton.

“He received three weeks’ training and the only safety equipment he had was sunscreen,” he said.

“Rueben Barnes died, and at Christmas there is an empty space at his father’s table.”

Those affected by the bungled scheme will be called to appear at the inquiry, however some testimonies may be made in private.

Counsel Assisting Keith Wilson QC says 76 parties have been summonsed to appear.

Public sittings are expected to be held in March and April next year, with the commission to deliver its findings mid-year.

Asked whether it made Christmas easier now that the commission was finally underway, four years after her son’s death, Mrs Fuller said: “It does help.”