Former deputy prime minister Tim Fischer is gravely ill in a southern NSW hospital.
Mr Fischer, 73, has been battling acute leukaemia and cancer generally for 10 years, The Australian reports.
He is currently being treated at the Albury-Wodonga Cancer Centre.
Last year he announced he was battling acute leukaemia, which followed a struggle with cancer in 2008.
"I can confirm I have been diagnosed with acute leukaemia and completing a 28-day cycle of treatment in the Peter Mac Hospital," he revealed in October.
"I am feeling okay but face further rounds of chemotherapy treatment."
In May, when he opened a museum dedicated to his life at his birthplace of Lockhart, near Wagga Wagga, he revealed he was hoping for a remission.
“Almost in remission, not quite. I am just uplifted by this nice gallery," he said at the time.
Mr Fischer, who first became an MP at the age of 24, was National leader from 1990 to 1999 and deputy prime minister in the Howard government from 1996 to 1999.
He quit politics in 2001.
The former Nationals leader and ambassador to the Vatican gave up most of his public roles and moved with wife Judy to a cattle farm at Mudgegonga, near Yackandandah in Victoria's northeast.
According to The Australian, Mr Fischer has previously battled bladder cancer, prostate cancer, melanoma and leukaemia in recent years.
Mr Fischer, who was born in Lockhart, NSW, in 1946, served in the Vietnam War, which he has previously said has contributed to his cancer diagnosis after exposure to the chemical Agent Orange.
Do you have a story tip? Email: firstname.lastname@example.org.