Six year’s after singer Whitney Houston’s death, her ex-husband has rejected her official cause of death saying he doesn’t believe drugs played a part in her accidental drowning.

A coroner ruled in 2012 that Houston’s demise was in part owed to the effects of “cocaine use”.

However, Bobby Brown has rejected the notion that drugs were a factor in her death, despite multiple substances being found in the singing legend’s system when she died in a Los Angeles hotel bathtub.

“I don’t think (Whitney) died from drugs,” he told Rolling Stone.

“She was really working hard on herself to try to be a sober person. She was a great woman.”

Brown, who was married to Houston from 1992 to 2007, was asked what he believes led to Houston’s death to which he responded: “Just being brokenhearted”.

Toxicology testing measured 0.58 micrograms of cocaine per milliliter of blood drawn from a vein in Houston’s leg during the autopsy, the Los Angeles County coroner’s office said in 2012.

As well as cocaine, toxicology results found marijuana, the anti-anxiety drug Xanax, the muscle relaxant Flexeril and the allergy medicine Benadryl in Houston’s body when she died, CNN reported at the time.

The autopsy report, which said Houston drowned in a foot of hot water, said the prescription drugs “did not contribute to the death.”

The Los Angeles County coroner ruled that Houston’s February 11 death was an accidental drowning with the “effects of atherosclerotic heart disease and cocaine use” as contributing factors.

Houston won six Grammys and sold more than 170 million records over her career.

In the interview, Brown also said he is also still awaiting justice over the death of his daughter with Houston, Bobbi Kristina Brown, who died in 2015 months after being found unresponsive in a bathtub at her Atlanta home.

An autopsy indicated that the pneumonia and brain damage that killed the 22-year-old was a result of drug intoxication and immersion.

Bobbi Kristina Brown’s then-boyfriend, Nick Gordon, was found legally responsible for her death but was not charged with a crime.