RICHMOND, Va. (AP) _ A judge ordered ABC to reveal the identity of a confidential tobacco industry source, giving a victory to tobacco giant Philip Morris in its $10 billion libel lawsuit against the network.

The source, dubbed ``Deep Cough,'' was featured in a ``Day One'' newsmagazine report last year that alleged Philip Morris Cos. and other tobacco companies spike cigarettes with extra nicotine to addict smokers.

ABC has previously identified the source only as a former manager for R.J. Reynolds Tobacco Co., a Philip Morris competitor. ``Deep Cough'' appeared on camera only in silhouette, and her voice was disguised.

In a hearing three weeks ago before Circuit Judge T.J. Markow, Philip Morris lawyers argued that learning the source's identity was crucial to proving malice and winning its lawsuit.

Markow's ruling Thursday said that because much of the story was based on the source's credibility, Philip Morris needs to know what she said, whether it was correct, and whether ABC knew if it was correct.

Markow also ordered ABC to reveal the identities of four other confidential sources cited in the broadcast.

The trial is scheduled for June 5.