A half-empty bottle of vodka and prescription medication were found in the California Comfort Inn hotel room where former Warrant rocker Jani Lane, 47, was found dead, TMZ.com reported.
His death is being investigated as a possible accidental overdose but may also have been from natural causes, the site reported.
An autopsy was performed by the L.A. County Coroner's office Friday, but an official said it did not reveal what caused the musician's death. Assistant Chief Coroner Ed Winter said the cause of death will be determined after results from toxicology and other tests are received. Winter says that process may take up to two months.
His family will convene Sunday for a private memorial service, Lane's manager and longtime friend Obi Steinman said. A public memorial with performances by fellow metal rock bands including Great White and L.A. Guns will be held in Hollywood on Aug. 24 at a venue to be announced later, he said.
The singer had a history of alcohol-related arrests, including one for crashing into a parked car in 2009.
His sister, Vicky Oswald-Ley, told RadarOnline.com that Lane had battled alcoholism for a decade but he "did not do drugs." She also told the site that although the family hasn't seen the autopsy report yet, "he was a heavy drinker and I can only guess that alcoholism has a lot to do with it."
Oswald-Ley also told the site that she believed the death of their mother seven years ago affected Lane's battles against alcohol. "She would always talk him into going to rehab and hospitals," she said. "I think when she passed, that desire to stay healthy died too."
She told Radar she believed Lane had gone to the hotel purely to drink, and said the family had not been contacted by Lane's manager or his wife of a year, Kimberley.
The band released a statement on its website, warrantrocks.com, saying, "We are deeply saddened to hear the news of Jani's passing. Our thoughts and prayers go out to his family. Jani was a very important part of our lives for a long time. We will always be incredibly proud of the music we created together. He was a true talent and will be missed by all of us."Story: Warrant singer Jani Lane, 47, found dead in hotel
The band also posted a five-minute video on YouTube highlighting Lane.
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The group will honor the musician at their Friday night concert with the band Skid Row in Grand Forks, N.D., TMZ reported.
Warrant is perhaps best known for the 1990 hit "Cherry Pie," written by Lane, reportedly in just 15 minutes. The song brought such fame to the band and so overshadowed their other music that Lane once told VH1 he was sorry he'd written it.Story: Hollywood reacts to reports of Jani Lane's death
He later retracted those comments, saying, "I'm happy as a clam to have written a song that is still being played and still dug by so many people."
Lane married model Bobbie Brown, who starred in the "Cherry Pie" video, in 1991 and they had a daughter. The couple divorced in 1993.
He left Warrant three times after joining them in 1986, finally leaving for good in 2008. The band released a new album, "Rockaholic," in May.
The Associated Press, TMZ.com and RadarOnline.com contributed to this report.
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