Labor says it's inconceivable that a senior minister did not tell the prime minister about the NBN Co AFP referral, despite Malcolm Turnbull's denials.
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.
