Steve Clark, 30; Guitarist With Def Leppard

Steve Clark, guitarist for the heavy metal rock group Def Leppard since shortly after it started in a garage 12 years ago, was found dead in his London apartment Tuesday, Scotland Yard said.

He was 30.

A spokesman for the British police agency said the cause of death was being investigated and that an autopsy would be conducted today. There was no evidence of foul play, the spokesman said.

Clark’s body was discovered lying on the living room floor of his apartment in the Chelsea district of London.

In New York City, Cliff Burnstein, one of Def Leppard’s managers, said the group had been recording in Ireland, and was taking a break in London.

Stephen Maynard Clark was one of the first members of the band, which was formed in 1978 by five teen-agers, all from Sheffield.

They got a record contract from Polygram in 1979 and their first album was a hit in the United Kingdom, reaching No. 51 in the United States.

Their precociousness (Joe Elliott, the lead singer and oldest member was only 19) attracted young fans around the world.

In 1983 their “Pyromania” album sold more than 6 million copies and by 1989 the group was reported to be earning $28 million a year.