The National Broadband Network (NBN) has stood by its chairman's decision to write an opinion piece during the election campaign, despite warnings from Government officials.

Key points: Ziggy Switkowski made "no apologies" for reporting alleged theft of documents

Ziggy Switkowski made "no apologies" for reporting alleged theft of documents Government officials raised concerns opinion piece would create unnecessary "noise"

Government officials raised concerns opinion piece would create unnecessary "noise" NBN chief supports Dr Switkowski's decision

Chairman Ziggy Switkowski wrote the article after police raids on the office of a Labor senator in May.

In the opinion piece, Dr Switkowski said he made "no apologies" for reporting the alleged theft of documents to federal police.

Police then conducted raids on the offices of then-senator Stephen Conroy — an outspoken critic of the Coalition's handling of the NBN — over the leaking of sensitive internal documents.

Head of the Department of Prime Minister and Cabinet Martin Parkinson said the piece was not consistent with caretaker conventions and Dr Switkowski was warned before it was published.

NBN representatives have told a Senate estimates hearing Government officials had raised concerns the opinion piece would create unnecessary "noise" during an election campaign.

But chief executive Bill Morrow said he supported Dr Switkowski's decision to go ahead with it.

"The chairman felt he was on solid ground to be able to make that decision, and we believe it was a good one that he made," Mr Morrow said.

"We believe all of the facts in the article that he had written were appropriate."

Senior NBN staff told the hearing it understood Government companies must comply with caretaker conventions unless that conflicted with a legal obligation or there were compelling organisational requirements.

But Mr Morrow said Dr Switkowski felt despite the fact that election campaign was underway, he needed to defend the company and its brand.

"We can see that these are purely guidelines, and that there are caveats within those guidelines about the agency head being able to make the ultimate decision as to what is right for their company," he said.

"We believe our chairman did just that."