The lead singer of US heavy rock band Drowning Pool, one of the main bands on Ozzy Osbourne's Ozzfest tour, has been found dead.

Dave Williams was discovered on the band's tour bus on Wednesday in Manassas, Virginia, according to a message on the band's website.

He cared more about his fans than most artists

Steve Karas Wind-Up Records

The cause of death was not immediately known and was being investigated by local police.

The band, from Dallas, Texas, had a growing loyal following both in the US and around the world, and their debut album, Sinner, has sold 1.2 million copies in the US since its release in June 2001.

The body of Williams, 30, was found by his bandmates when he did not emerge to check into a hotel, police said.

"He was somebody who knew how to entertain," Steve Karas, a spokesman for the band's record label Wind-Up said.

Their album, Sinner, earned them a loyal following

"He cared more about his fans than most artists and, genuinely, in his heart, gave everything he had every time he was on stage."

The band were in the middle of the US leg of the Ozzfest tour, a giant festival-style all-day roadshow featuring more than 20 bands and led by former Black Sabbath frontman Ozzy Osbourne.

Drowning Pool were fifth on the bill, behind Osbourne, System Of A Down, former White Zombie frontman Rob Zombie and POD.

The latest gig is scheduled to take place in Bristow, Virginia, on Thursday.

Williams was the last member to join the band, which was founded by drummer Mike Luce and guitarist CJ Pierce.

'Horrible'

He was nicknamed "Stage" by fellow rock band Pantera because of his powerful and emotional live performances.

The band found success with their debut single, Bodies, after touring extensively and honing their raucous, alienated sound.

Fans have been leaving messages on the band's website after learning of the news.

"Personally I feel horrible. The world has lost yet another speaker of our generation," one said.

Another wrote: "It's hard to watch these small town boys finally make it, and lose the singer so soon."

One who said they met the singer wrote: "Dave made everyone he met that night feel like he was their friend. I can't believe he's gone."