Labor senator Stephen Conroy has called for NBN Co chairman Ziggy Switkowski to resign over what he claims were "illegal" AFP raids on his office as part of an investigation of leaked NBN documents.

Speaking on ABC's RN Drive program last night, the former Communications Minister "demanded" an apology from both Switkowski and current Communications Minister Mitch Fifield over the affair, as well as the NBN chairman's resignation.

He argued the May police raids on his own office and the home of a staffer of Shadow Communications Minister Jason Clare were illegal given NBN Co was not a Commonwealth officer and lacked the power to make referrals to the AFP.

"I've written to the federal police on Friday, asking them to end their ludicrous investigation into leaks from the NBN on the basis of legal advice that says NBN Co have incorrectly called the police in," Conroy said on radio.

"They are not Commonwealth officers and I'm seeking and demanding an end to the investigation and an apology from Ziggy Switkowski, an apology from Mitch Fifield who's overseen this, and that Ziggy Switkowski resign over it."

Switkowski was found to have knowingly breached caretaker conventions when he published an opinion piece defending the AFP investigation into the leaked documents. The Department of Prime Minister and Cabinet has no legal recourse to take action against the chairman.

On the same program Fifield said he 'would not be apologising to Stephen' for the "very reasonable" and "perfectly entitled" police raids.

"I didn't raid Stephen's office, the Australian Federal Police did. The referral from the NBN to the AFP was a matter for NBN, and the AFP determine what is and is not within their jurisdiction," Fifield said.

"It's entirely a matter for the Australian Federal Police. They have operational independence, and to question the AFP and their motives is to question the integrity of that organisation."

Two NBN Co employees were stood down over the series of internal documents that were leaked over several months from last November. NBN Co asked the police to intervene in December after it failed to internally identify the culprits.

The leaked documents included an internal progress report that revealed the NBN was running behind on its fibre-to-the-node rollout. Another detailed the company's plan to overbuild the degraded Optus HFC network, while a third revealed the remediation bill for Telstra's copper would likely be ten times more than expected.

The investigation is currently on hold after Conroy made a claim of parliamentary privilege over documents seized by the AFP.