The autopsy of former Warrant singer Jani Lane was performed on Friday. However, the result proved inconclusive pending the results of toxicology tests, according to the Los Angeles County coroner's office.

Jani Lane, 47, the former Warrant singer, was found dead in a Woodland Hills motel room Thursday night.

It will take seven or eight weeks to finalize the cause of Lane's death, Assistant Chief Coroner Ed Winter said. However, there is no indication he committed suicide, the police sources said.

But some of Lane's close friends feel the singer could have succumbed to alcohol addiction. "He lost his battle over alcohol," Lane's longtime friend and manager Obi Steinman said.

According to the police sources, there are alcohol and prescription drugs found in the room he died. Also he had been struggling with substance issues and ranked up at least two DUI arrest.

Steinman paid tribute for his friend, "He was one of the great rock-and-roll frontmen and singers of all time," he said. "His music helped shape the '80s."

Warrant's current members also paid tribute with a concert Friday night in North Dakota. "We never thought that when the song 'Heaven' was written we would be playing it someday in the memory of Jani's untimely death," guitarist Erik said with TMZ. "This is a very sad day for rock and roll."

"We'd like to offer our deepest condolences to the family of Jani Lane regarding their loss. Respectfully, Bret and all at MEGI," Bret Michaels tweeted.

"Jani Lane's is yet another sad story of a boy who attained his dreams of greatness, only to be blindsided by the pressures, temptations and disappointments of those same dreams," wrote Twisted Sister's Dee Snider.

"We all watched over the years, as he soared, stumbled, fell, then got up again and again. Tragically, he will get up no more. RIP Jani."

 "R.I.P. Jani Lane...a true songwriter and one of the most underrated voices in rock n roll, unfairly looked over because of hair metal tag," Mark "Sugar Ray" McGrath added.

Lane's family will hold a private memorial service on Sunday and a public memorial in Hollywood, featuring performances by other metal bands such as Great White and L.A. Guns , will be held Aug. 24, Steinman said.

Jani Lane is a former singer of the band "Warrant", which delivered hits such as "Cherry Pie," "Uncle Tom's Cabin" and "Heaven." Lane divorced twice, having two daughters. He was featured on VH1's "Celebrity Fit Club 2" in 2005.