Labor frontbencher Linda Burney will take leave from Parliament after her 33-year-old son was found dead in the family home on Tuesday night.
In a statement, Ms Burney asked for privacy "in this dire, grief-stricken time" and said NSW Police had advised there were no suspicious circumstances surrounding the death.
"I wish to advise that my beloved son, Binni Kirkbright-Burney was found dead last night at our family home in Sydney," she said, describing him as a "caring and loving man".
"I returned to Sydney last night to be with him this one last time ... He has struggled with mental health and with addiction. He tried so hard to conquer his demons, as I and my family have tried so hard to support him in every way we could.
"I don't want to pre-empt a subsequent inquiry but we all thought we were getting somewhere. I don't know what life will be like without him."
Ms Burney is the opposition's human services spokeswoman. She entered federal politics after 13 years in NSW Parliament, where she became deputy leader of the Labor Party.
As a descendant of the Wiradjuri people, the MP for the Sydney electorate of Barton is the first Aboriginal woman elected to the federal House of Representatives.
Opposition Leader Bill Shorten extended his condolences to the Burney family on Wednesday morning.
"I can't imagine what it's like as a parent to lose your child. I know how much her son loved Linda and how much Linda loved her son," Mr Shorten said.
Last year, in her first speech to the House of Representatives, Ms Burney said her pride and love for her son Binni and daughter Willurai was "more than all the stars in the sky".
Her partner Rick Farley, a civil rights activist and former head of the National Farmers Federation, died in an accident in 2006. He fell from his wheelchair months after suffering from a brain aneurysm.