A bureaucrat has told an inquiry that training for home insulation installers was taken seriously, but he can’t recall what was done to monitor it.

A bureaucrat charged with monitoring the home insulation scheme’s rollout says he was put in his place when he raised the issue of installer training with the department devising the scheme.

Simon Cox was seconded to the co-ordinator general’s office to oversee the program being developed by federal environment department staffers.

Mr Cox told the royal commission into the troubled scheme that he had a “vague recollection” of what he did to follow up on the issue of training.

He said he only had a “general sense” that he and another public servant were monitoring it.

But Commonwealth lawyer Tom Howe QC showed the inquiry an email in which Mr Cox requested updated information on training requirements from the environment department.

Mr Cox then agreed he was put in his place by a senior environment department bureaucrat who delivered a gentle rebuttal that said others would soon report on the subject of training.

During cross-examination, Counsel Assisting Keith Wilson said it “beggared belief” that Mr Cox had little recollection of how he followed up on the issue of training.

But Mr Cox said he had nothing to hide from the royal commission.

“It was five years ago and it was only a short period in my life,” he said adding he couldn’t help what he could not remember.

The inquiry, which is in its second week, is investigating what warnings the government received about the program and whether the deaths of four installers could have been avoided.

Queenslanders Matthew Fuller, Rueben Barnes and Mitchell Sweeney, and Marcus Wilson from NSW, died while working under the scheme that’s also been blamed for at least a hundred house fires.

Mr Cox also told the inquiry that bureaucrats were relieved to learn that the National Code of Practice for the construction industry wasn’t applicable to the home insulation scheme.

It was considered good news, he said, because if the code applied then the program would have come to an “immediate halt”.

This was because insulation providers would have been required to undergo checks to determine whether they complied with the code.

The inquiry also heard evidence from Martin Hoffman, who worked in the Department of Prime Minister and Cabinet when the insulation scheme was devised.

Mr Hoffman was asked on Tuesday whether Senator Mark Arbib wanted to derive as much stimulus as possible out of the program.

He said Mr Arbib didn’t express this view to him, although the senator was focused on stimulating the economy.

Mr Arbib, former prime minister Kevin Rudd and environment minister Peter Garrett are all set to appear before the royal commission.

Mr Hoffman will continue his evidence when the royal commission before Ian Hanger QC resumes on Wednesday.