It has been a bitter and painful process for Aboriginal parliamentarians to try to prove their eligibility as citizens.

"It was gut wrenching," Labor MP for Barton Linda Burney said today.

Northern Territory senator Malarndirri McCarthy has her mother's death certificate but not a record of her mother's birth because records were not kept.

All MPs have had to fill in forms to show they are not dual citizens but for Aboriginal MPs, including Senator McCarthy and Ms Burney, much of the documentary evidence does not exist.

"The reason why there are no documents and birth certificates is because we were not considered citizens in this country," Senator McCarthy said.

She said trying to find the paperwork to prove she was eligible at times caused incredible angst and outrage.

"I didn't know the answers to these questions," she said.

Senator McCarthy's mother was born in 1950 on Manangoora Station, which is on Yanyuwa country near Borroloola in the Northern Territory, but she does not have an exact date.

Without the sort of birth records non-Aboriginal Australians received as a matter of course, Senator McCarthy's mother chose her own birthday.

"The reason why I didn't know the answers to the questions about my maternal grandparents and the year they were born and even the year my mum was born is simply because documentation in terms of birth certificates were not a part of our existence," she said.

For the senator, "There is a lot of sadness" in having a record of her mother's death, but not an official document about her birth.

While Senator McCarthy needed the non-existent records to prove her right to be in Parliament, she said many of her constituents in the Northern Territory faced similar problems gaining the identity documents society demanded for ordinary daily tasks like opening a bank account.

Ms Burney said the only way she could find records of her paternal grandfather were to go to the New South Wales Protection Board records.

Her grandfather lived on a reserve and had to apply to the mission manager for permission to build a home and to the Protector of Aborigines for an exemption certificate, "which we called the dog tag".

"That was the only evidence I could find and luckily, on the application for the permission to build a home, my father and his age were recorded," Ms Burney said.

"It was gut wrenching and it made me think what it was like for generations that lived under that Protection Act," she said.

Ms Burney said she was not arguing for an Indigenous exemption from the parliamentary process.

"I'm just saying that this exercise for a lot of people has not been without a lot of distress," she said.

ABC Online:http://www.abc.net.au/news/2017-12-05/aboriginal-parlimanetarians-describe-painful-citizenship-process/9228506