The U.S. military viewed anti-secrecy website WikiLeaks as a news gathering operation before Private First Class Bradley Manning leaked a trove of classified files to it, a Harvard professor testified at Manning's court-martial on Wednesday.

Yochai Benkler, a Harvard University law professor and expert on media law, testified for the defense that a 2008 Defense Department report on WikiLeaks had said that a U.S. enemy could theoretically use the site to gather information.

But the Pentagon report, which had been based on publicly available material, said there was no sign that that had happened, said Benkler, the co-director of the Berkman Center for Internet and Society.