An autopsy on the body of Christian Brando performed at the request of his estranged mother has brought no immediate results, authorities said Tuesday.

Christian Brando, 49, the eldest son of the late actor Marlon Brando, died Saturday, Jan. 26, at a Los Angeles hospital. An attorney for Marlon Brando's estate said Brando died of pneumonia.

However, according to the Associated Press, Los Angeles County coroner's official Ed Winter said the cause of death was listed as deferred, pending results of toxicology tests that may determine whether the 49-year-old had prescription or other drugs in his system and whether a medical condition was involved.

Brando's mother, Anna Kashfi, requested the autopsy, lawyer David J. Seeley said, adding that neither the estate nor its beneficiaries were involved in the decision. “At this point, we have no reason to question the hospital's actions and the cause of death,” Seeley said.

Los Angeles County coroner's Lt. Fred Corral said Monday that the autopsy was requested “based on his past drug history,” reports the AP. Results will be available in six to eight weeks.

Christian Brando somewhat followed in his father’s footsteps, with small roles in “The Secret Life of an American Wife” and “I Love You, Alice B. Toklas!” but his adult years were marred by tragedy, as in 1990 he shot to death the boyfriend of his half-sister Cheyenne.

He was convicted of voluntary manslaughter and spent five years behind bars. Cheyenne committed suicide in 1995.

Christian Brando was one of nine children, by different women, named as beneficiaries of Marlon Brando's trust. Brando, who passed away in 2004 at the age of 80, noted in his will that he had 11 children and an adopted daughter who was not a beneficiary.

Kashfi and Marlon Brando divorced after a year of marriage; Kashfi and Christian Brando were estranged for 20 years.

The story gets even sadder, as Brando’s former wife Deborah Brando, filed a suit Monday in L.A. County Superior Court, alleging that executors of the Marlon Brando estate had altered it, in an attempt to deceive her and not give her her share of property.

Deborah Brando claims she is a victim of fraud and deceit, conspiracy and professional negligence and is asking for an unspecified amount.

She and Christian Brando ended their two-year marriage in 2005, following the actor’s conviction of spousal abuse.

The AP quotes Seeley as saying that the estate will “vigorously defend” against the lawsuit.