Newsted: Quit the band, blaming "physical damage"

"We would like you all to know that James Hetfield has entered a rehabilitation facility to undergo treatment for alcoholism and other addictions," the statement said.

"James has entered an undisclosed facility, and he will continue to receive treatment until further notice."

Recording sessions had begun in April, but they have now been put on hold, it said.

"James is working hard toward recovery. We trust that you will appreciate the sensitive nature of this matter, and respect our wishes to give James the time and privacy he needs to deal with his problems."

Now a trio

The site earlier said Hetfield had just returned from bear hunting in Russia, and that he said he was "alive, safe and back".

Newsted's decision to leave in January meant the remaining band members were Hetfield, lead guitarist Kirk Hammett and drummer Lars Ulrich.

Hammett said at the time of Newsted's departure that the band was looking forward to "embracing the next chapter of Metallica".

Their latest studio album had been due for release in late 2001 or early 2002.

Tour tragedy

Founded in California in 1982, Metallica took their influences from UK acts of the time like Motorhead and Diamond Head.

Just as the band were becoming worldwide stars, original bass player Cliff Burton was killed when the band's tour bus crashed in Sweden.

They have sold 55 million albums worldwide and picked up five Grammy awards.

More recently, Ulrich has become a leading figure in the campaign against internet song-swapping service Napster.

And the group also expanded its repertoire by teaming up with composer Michael Kamen and the 104-member San Francisco Symphony Orchestra to perform Metallica compositions.