No cause of death has been released.
Reuters repored that Lane, the blonde-haired lead vocalist and author of the glam band's hits such as "Cherry Pie," was found dead in a Los Angeles motel room in Woodland Hills Thursday night. He was 47.
Warrant was among the class of big-hair bands of the 1980s and 1990s, scoring monster hits of "Sometimes She Cries," "Uncle Tom's Cabin" and "Bed of Roses."
Lane, who was born in Ohio, left Warrant several times, including in 1993 and 2004. He returned to the band for a series of concerts in 2008 then left for good, going out on a solo career.
Hollywood Gossip reported that Lane had been dealing with alcohol problems. In 2010, the magazine reported, Lane was sentenced to four months in jail after his second DUI arrest in two years.
Lane was reportedly working on new music, according to a post on his website.
On the band's website, Warrant members posted: "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."