Indigenous leader Marcia Langton wants the federal opposition leader to remove a social media image claiming she branded 'no' voters racist and stupid.
The image of Professor Langton standing next to Prime Minister Anthony Albanese includes the words "No Voters Branded 'Racist, Stupid' By Prominent Voice Campaigner Marcia Langton" below the logo of The Australian newspaper.
"I will have to ... ask a lawyer to write to Peter Dutton requesting that he remove this post from his Instagram because it is absolutely not true," Prof Langton told ABC radio on Wednesday.
The furore relates to remarks she made at a forum in Western Australia on Sunday on the October 14 referendum on an Indigenous voice to parliament.
"Every time the 'no' cases raise their arguments, if you start pulling it apart, you get down to base racism - I'm sorry to say that's where it lands - or sheer stupidity," Prof Langton told the forum.
"If you look at any reputable fact-checker, every one of them says the 'no' case is substantially false, they are lying to you."
Deputy Liberal leader Sussan Ley told parliament on Tuesday Prof Langton had labelled "those advocating a no position as either 'racist' or 'stupid'."
"I challenge anyone to consider those remarks and not feel insulted by them," she told Sky News on Wednesday, adding that the coalition wasn't part of the official 'no' campaign.
Ms Ley also repeated her call for Indigenous Australians Minister Linda Burney to remove Prof Langton from the government's referendum working group for "denigrating" the 'no' campaign.
"We need a respectful debate," she added.
Treasurer Jim Chalmers accused Mr Dutton of distributing misinformation during the voice campaign.
"The leader of the opposition has taken the weirdest whispers from the further fringes of social media and legitimised them and amplified them here in the people's house of parliament," he said.
"This will drag out for as long as possible so the leader of the opposition can drip more poison into the well. That's how he seeks to divide and diminish this country and reap a political dividend."
The treasurer said the referendum would be a once-in-a-generation opportunity to create meaningful change.
Prof Langton said her comments were taken out of context and were referring to 'no' campaign tactics, not people intending to vote 'no'.
"There is a recording of what I said at the Bunbury meeting and what I said is very clear - I was explaining how the 'no' campaign is using fear and lies to frighten voters into voting no."
Prof Langton said it was racist to say that if someone voted 'yes', Indigenous people would get compensation.
"Nobody, not Aborigines, not anybody, gets compensation unless they are legally entitled to it," she said.
"The no case is implying that if you vote 'yes', Aborigines, even if they are legally entitled to compensation, will get that compensation ... so it is the 'no' campaign that is promoting division on the basis of race."
The image posted on Tuesday to Mr Dutton's Instagram account included comments attributed to the leader.
"Australians are genuinely concerned about the unknown consequences of Labor's risky Voice proposal, which is the biggest constitutional change in our history," the post said.
"The prime minister should condemn these comments from leading voice advocate Marcia Langton."