Updated

LONDON -- Newly released documents show that a legal adviser to Rupert Murdoch's newspapers warned the company three years ago that several senior journalists at the News of the World were using illegal methods.

British lawmakers investigating the phone hacking scandal on Tuesday released a copy of the opinion provided to Murdoch's company by lawyer Michael Silverleaf in 2008.

In it, Silverleaf says there is "overwhelming evidence of the involvement of a number of senior ... journalists in the illegal inquiries."

Executives at the company insisted until early this year that phone hacking had been the work one rogue reporter. Murdoch shut down the tabloid in July after evidence emerged it was much more widespread.