AceShowbiz - Filmmaker Kevin Macdonald has insisted Whitney Houston's death was more mysterious than initially reported.

The legendary singer passed away at the age of 48 after she was found unconscious in a bathtub. The Los Angeles County Coroner's Office listed her death as an "accident" caused by drowning and the "effects of atherosclerotic heart disease and cocaine use," while toxicology results discovered substances including Benadryl and Xanax in her system.

However, Macdonald, whose documentary Whitney has been met with rave reviews so far, uncovered some unusual information regarding the circumstances surrounding her death.

"There was discussion about the death, which was so mysterious," the Scottish filmmaker explained in an interview with NME. "Mary Jones, her assistant, told me that she thought there might have been someone else in the room when Whitney died, because there was so much water on the floor, but the taps in the bath were off. The taps had been on for the bath to overflow, but who switched them off?"

Macdonald recalled speaking to "various dodgy individuals" who were present in the lead up to the tragedy, but ultimately decided to omit the footage to keep in line with the movie's overall themes.

"It felt like a very long 15 minutes at the end of the film. It felt like that wasn't what the film was about," he insisted. "I think the film became about the family."

Earlier this year, Houston's ex-husband of 14 years Bobby Brown expressed cynicism regarding the coroner's reports, and was adamant that drugs were not to blame for the Grammy Award winners death.

"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."

The couple's daughter Bobbi Kristina Brown also died in similar circumstances at the age of 22, when she was found face down in a bath tub in July 2015.