TMZ said Lane's body was discovered Thursday night. The cause of death had not been disclosed.
Lane wrote the band's signature song "Cherry Pie," a big hit in 1990. He left the group in 2004 to pursue a solo career but returned in 2008, leaving again that same year due to differences with his fellow musicians.
He was ordered to serve 120 days in jail after he was arrested for driving under the influence last year. It was his second DUI conviction in two years, TMZ said.
Warrant's other hits include "Heaven," "I Saw Red" and "Sometimes She Cries."