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OTRC: Whitney Houston's sister-in-law Patricia: 'We are saddened' by toxicology results

Patricia Houston appears in a photo from her interview with Oprah Winfrey in March 2012. (OWN)

Whitney Houston's sister-in-law Patricia Houston says her family is "saddened" to learn about the toxicology results of the singer's death, which revealed that the pop star had used cocaine before she died last month.

Los Angeles County Chief Coroner Investigator Craig Harvey said on Thursday, March 22, that Houston had battled substance abuse for years and relapsed in May 2011. She had "a moderate level" of cocaine in her system when she was found underwater and unresponsive in a hotel room bathtub on February 11, Harvey said, adding that the toxicology results suggested "chronic" use.

The official cause of her death was accidental drowning and the drug and a pre-existing heart condition were listed as contributing factors.

"We are saddened to learn of the toxicology results, although we are glad to now have closure," Patricia Houston said in a statement obtained by OnTheRedCarpet.com.

The woman, who was also the singer's manager and is married to Whitney Houston's brother Gary, earlier this month talked about Whitney Houston's death in an interview with Oprah Winfrey on hers OWN show, "Oprah's Next Chapter."

"The handwriting was kind of on the wall," she said. "I would be kidding myself to say otherwise. Things were really changing with her. Very much so. It wasn't about substance abuse or anything like that relative to the latter -- the latter days or anything like that. I think it was - it was just more of a lifestyle."

Whitney Houston is survived by daughter Bobbi Kristina, 19, and ex-husband, singer Bobby Brown. Her family was notified about the toxicology results before they were released to the press, Harvey said, adding that a full autopsy report is expected to be published within two weeks.

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