NEW YORK - Wall Street swindler Bernard Madoff has told fellow prison inmates that he is dying of cancer, the New York Post reported Monday, citing unnamed prison sources.

Madoff, 71, who since June has been serving a 150-year sentence at a North Carolina federal prison, has been telling inmates that he does not have long to live, the newspaper said, citing the unofficial and unusual sources.

One inmate at the Butner (North Carolina) Medium Federal Correctional Institution said Madoff was taking about 20 pills a day and not doing very well, the Post wrote.

Federal Bureau of Prisons spokeswoman Traci Billingsley said the Post story was inaccurate, but she could neither confirm nor deny details about Madoff's health. She said the bureau was seeking Madoff's permission to disclose details about his medical condition.

Madoff lawyer Ira Sorkin was not immediately available for comment. The Post said Sorkin had previously declined to answer questions about whether Madoff had cancer.

The newspaper said there was speculation earlier this year that Madoff was suffering from pancreatic cancer.

The tabloid also reported that Madoff has engaged in a number of surprising new activities with some unexpected social circles.

A shirtless Madoff has joined weekly Native American religious purification ceremonies that involve prayers, heated rocks to induce sweat, and smoking from a ceremonial pipe, the paper said.

The Bureau of Prisons spokeswoman confirmed Butner does provide a sweat lodge as a religious structure for Native American prisoners.

The paper also reported that various gangs at the prison were trying to recruit Madoff, while some inmates regularly cook sandwich wraps for him at their cells.

The spokeswoman said inmates are not permitted to prepare food in their cells, though it may be procured in the prison commissary and brought back to the cells.

Madoff pleaded guilty in March to orchestrating a worldwide $65 billion Ponzi scheme over 20 years.

(Reporting by Joseph A. Giannone, editing by Maureen Bavdek and John Wallace)