Labor is demanding to know if Malcolm Turnbull was aware of an Australian Federal Police investigation into NBN Co leaks after a senior minister revealed he had been briefed.
Communications Minister Mitch Fifield confirmed he knew about the December referral of leaked secret documents to the AFP but insists he did not tell the prime minister or other ministers.
The prime minister on Saturday backed up his senior minister's account, telling journalists it was "entirely appropriate" for Senator Fifield not to advise him of the matter.
He has emphatically denied having any knowledge of the investigation.
But Labor isn't buying it.
Opposition Leader Bill Shorten said it was inconceivable Senator Fifield did not advise the office of the prime minister, who had carriage of the NBN until last year as communications minister.
"It is either gross incompetence or far worse and we are not being told the truth," he told reporters in Sydney on Saturday.
The investigation exploded onto the public radar on Thursday when AFP officers raided Labor senator Stephen Conroy's office and the home of a staffer in Melbourne, seizing several documents.
The late-night raid two weeks into an election campaign raised questions about the AFP's timing and sparked Labor allegations the Turnbull government could be behind it.
It's since been revealed an NBN Co employee - who assisted police in the raid - took 32 photographs of the secret items, which have now been sealed under a claim of parliamentary privilege.
It's understood those photos have been deleted from the staffer's mobile phone, but Labor is demanding to know where they were went and who still has copies.
As he rounded out two weeks on the campaign road, Mr Turnbull tried to field questions from journalists about other topics but was plagued by queries about who knew what and when.
Labor says the "explosive revelations" by Senator Fifield showed the government's attempt to run from the matter had "hit the fan".
Senator Fifield, who knew about the matter for several months, insists he has played no part in the investigation.
"The referral to the AFP was made by the NBN senior management," Senator Fifield said.
"I did not instruct nor request them to do so.
"As an AFP investigation was underway, I did not advise other ministers or the prime minister of this matter."
Police have been investigating the leaking of confidential documents about the national broadband network after the matter was referred from NBN Co last December.
The documents can't be analysed by police until the Senate decides if parliamentary privilege does apply.
Mr Turnbull questioned the process by which Senator Conroy was claiming privilege, saying documents were normally tabled in parliament.
"I don't want to get into the legalities of Senator Conroy's determination to keep the police away from these documents, which were clearly stolen from the NBN Co," he said.
"He's trying to keep the police away from those."
Opposition frontbencher Penny Wong accused the prime minister of trying to make light of the claim.
"Parliamentary privilege isn't the plaything of any government or any political party," she told reporters in Melbourne.
"It is a principle that's been around for many centuries."
The AFP has confirmed the NBN staffer who took the photos of the secret documents was under the direction of police at all times during the search.
