Senator Stephen Conroy's Melbourne office is among Labor party premises in Melbourne raided by Australian Federal Police over alleged leaked NBN documents.
Opposition Leader Bill Shorten confirmed the AFP raids on Thursday night, saying they were being carried out in relation to the leaking of confidential National Broadband Network documents.
"It relates to his (Prime Minister Malcolm Turnbull) embarrassment over the fact there was a massive blowout of costs of billions and billions of dollars and, of course, huge delays to the delivery and the rollout of the NBN," Mr Shorten told reporters in western Sydney.
In February Fairfax Media, quoting an internal NBN progress report, claimed the $46 billion network had fallen two-thirds short of its benchmark construction timetable.
Shadow attorney-general Mark Dreyfus said on Thursday night two Labor staffers had also been named in warrants relating to leaked documents.
Fairfax Media reports they are both staffers for Labor's communications spokesman Jason Clare, one of whom is a former staffer to Senator Conroy.
Mr Dreyfus, who earlier cancelled a planned press conference in Melbourne, said many other serious government leaks relating to national security, defence and the federal budget had been raised previously - but none of them resulted in AFP raids.
He described Thursday night's events as "unprecedented" - especially during an election campaign.
Prime Minister Malcolm Turnbull said the raids were "entirely" a matter for the AFP.
"The Labor Party know that as well as you and I do," he said on Thursday night.
AFP confirmed raids were being conducted in Melbourne but would not expand on where or what was being targeted.
"As this activity is related to an ongoing investigation, it is not appropriate to comment any further at this stage," an AFP spokesman said in a statement.
The NBN Co said it was assisting the AFP with an ongoing investigation but it wasn't appropriate to comment any further.