Robert Durst, the wealthy New York real estate heir and failed fugitive who was dogged for decades with suspicion in the disappearance and deaths of those around him before he was convicted of killing his best friend and sentenced to life in prison, has died. He was 78.

Durst died in a state prison hospital facility in Stockton, his attorney Chip Lewis said.

He said it was from natural causes due to several health issues.

Durst was convicted in September of shooting Susan Berman at point-blank range in 2000 at her Los Angeles home.

He was sentenced to life on October 14. Two days later, he was hospitalised with COVID, his trial attorney Dick DeGuerin said.

Durst had long been suspected of killing his wife, Kathie, who went missing in 1982 and has been declared legally dead.

He was finally indicted in November for second-degree murder in her death.

Prosecutors in Los Angeles presented evidence Durst silenced Ms Berman because she helped him cover up Kathie’s killing and was about to talk to investigators.

They also argued he killed a Texas man who discovered his identity when he was living secretly in Galveston after Ms Berman’s killing.

Durst was acquitted of murder in that case in 2003, after testifying he shot him in self-defence.

Durst had bladder cancer and his health deteriorated during the Berman trial. He was escorted into court in a wheelchair wearing prison attire each day because his lawyers said he was unable to change into a suit. But the judge declined further delays after a 14-month pause during the coronavirus pandemic.

Mr DeGuerin said Durst was “very, very sick” at his sentencing hearing and it was the worst he looked in the 20 years he spent representing him.

The son of real estate magnate Seymour Durst, Robert Durst was born April 12, 1943, and grew up in Scarsdale, New York. He would later say that at age 7, he witnessed his mother’s death in a fall from their home.

He became a developer in the family business, but his father passed him over to make his younger brother, and rival, Douglas, the head of the Durst Organisation in 1992.

In 1971, Robert Durst met Kathie McCormack, and the two married on his 30th birthday in 1973.

In January 1982, his wife was a student in her final year at medical school when she disappeared.

He would divorce her eight years later, claiming spousal abandonment. In 2017, at her family’s request, she was declared legally dead.

Robert Durst is survived by his second wife Debrah Charatan, whom he married in 2000. He had no children.

-AAP