Updated

The son of the late New York City philanthropist Brooke Astor, who was convicted of defrauding her, has been classified as eligible for medical parole because of his frail health, according to the Department of Correction.

Anthony Marshall, who is 89 and depends on a wheelchair, is scheduled to go before a parole board the week of Aug. 19.

Marshall surrendered on June 21 and last month began serving a one- to three-year prison sentence at the Fishkill Correctional Facility in Beacon, about 70 miles north of New York City. He had been convicted on charges of taking advantage of his aging mother's slipping mind to loot her multimillion-dollar fortune.

Marshall suffers from Parkinson's disease and congestive heart failure. He lost a series of bids to get a new trial or to get his prison term nixed because of his failing health. He applied for medical parole soon after starting his sentence. State law allows medical parole for inmates who are terminally ill or have serious and permanent illnesses.

The Manhattan district attorney's office declined to comment on his medical parole application.

Astor died in 2007 at age 105. She had inherited the money from her third husband, a descendant of real estate and fur baron John Jacob Astor. She was a fashionable fixture of New York society, and her charitable largesse was recognized in 1998 with the Presidential Medal of Freedom, the nation's top civilian honor.

Marshall, who was wounded while leading a Marine platoon in the battle of Iwo Jima, later became a U.S. ambassador and Broadway producer. He was Astor's son from her first marriage, and the trial portrayed a fraught relationship between son and mother.

Marshall and Francis Morrissey Jr., a former estate lawyer accused of forging Astor's signature on a change to her will, were convicted in 2009.