Women's Safety Minister Anne Ruston says the government is investigating Grace Tame's claim that she received a "threatening" phone call asking her not to say anything controversial about Prime Minister Scott Morrison.
In her address to the National Press Club alongside Brittany Higgins, Ms Tame said a senior member of an organisation funded by the government asked her last year not to say anything negative about Mr Morrison.
She said the caller was "asking for my word that I would not say anything damning about the Prime Minister on the evening of the next Australian of the Year awards".
"'You are an influential person. He will have a fear,' they said. What kind of fear, I asked myself?"
"And then I heard the words 'with an election coming soon'."
The former Australian of the Year declined to name which organisation the person worked for.
Senator Ruston said an investigation "has already been commenced".
"I was unaware of the accusations until I heard them today at the Press Club and my understanding is that no one else in government was aware of that until that time," she said.
"Obviously it is an unacceptable thing for any agency that is funded by government who is seeking to do that, to anybody.
"I think we need to find out the circumstances around exactly what's happened and transpired here but obviously the consequences need to match up with the action that's been taken."
In a Tweet, Ms Tame said an investigation into who made the call "is the very same embedded structural silencing culture that drove the call in the first place and misses the point entirely".
A spokesperson for the Prime Minister said the first Mr Morrison and his office became aware of the allegation was during Ms Tame's speech.
"The Prime Minister has not and would not authorise such actions and at all times has sought to treat Ms Tame with dignity and respect," they said.
"The Prime Minister and the government consider the actions and statements of the individual as unacceptable."
The spokesperson also said the individual who made the call should apologise.
