NEW YORK — The elderly son of Brooke Astor, who is one month into a prison sentence for swindling his late philanthropist mother, has been granted an interview for possible medical parole, a Department of Corrections spokesman said on Tuesday.

Anthony Marshall, 89, began serving a one- to three-year sentence on June 21 for stealing millions of dollars from his socialite mother, who suffered from Alzheimer’s disease. He will appear before the parole board on Aug. 19, said Tom Mailey, a spokesman for the New York State Department of Corrections and Community Supervision.

Marshall, a decorated World War II veteran who was a Broadway producer and U.S. diplomat, has been serving his sentence at the Fishkill Correctional Facility, a prison nursing home some 70 miles north of New York City.

Brooke Astor, widow of Vincent Astor, heir to the fur and real estate fortune of John Jacob Astor, was a well-known philanthropist who summered in the Maine village of Northeast Harbor for decades before she died in 2007 at the age of 105. She gave away $200 million during her lifetime, including some to organizations on Mount Desert Island. Astor left money in her will to College of the Atlantic, Asticou Azalea Garden, Northeast Harbor Library, and to Saint Mary’s and Saint Jude’s Parish.

Marshall was in a wheelchair when he turned himself in to authorities in June. In a final attempt to keep him out of prison at the time, his lawyer said that his inability to walk or feed himself made him too frail for incarceration.

“It would be a cruel and unusual punishment to be sentenced to jail at his age, in his condition,” Marshall’s lawyer Kenneth Warner told a judge in Manhattan federal court. “The reality is that … he is a feeble and frail 89-year-old.”

Marshall was convicted in 2009 of grand larceny and other charges for keeping his socialite mother in squalid conditions in her final years and for taking advantage of her deteriorating mental state for his own financial gain.

A spokeswoman for the Manhattan district attorney’s office, who prosecuted Marshall for looting Astor’s fortune, declined to comment on the parole board’s agreement to interview Marshall.

Marshall’s attorney did not immediately return a call seeking a comment.