Army Private Bradley Manning is escorted into a courthouse in Fort Meade, Maryland. File photo: Patrick Semansky, AP

FORT MEADE - The US 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 US 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.

The Pentagon report came out before Manning, 25, is alleged to have leaked more than 700 000 classified files, combat videos and State Department cables while serving as an intelligence analyst in Iraq in 2009 and 2010.

Benkler is the 10th witness called by chief defense lawyer David Coombs since he started his case on Monday. Coombs has not divulged a customary list of witnesses, but Benkler could be the last called by the defense.

The 21 charges against Manning include espionage, computer fraud and, most seriously, aiding the enemy by disclosing material that could be used by the al Qaeda extremist network.

Manning, a native of Crescent, Oklahoma, could face life in prison without parole if convicted of aiding the enemy.

In other testimony, a specialist at the Center for Army Lessons Learned at Fort Leavenworth, Kansas, said in a sworn statement that the center had not recommended changes, such as in training or tactics, because of the WikiLeaks disclosures.

The center, which focuses on adapting operations to changing conditions, also had not been requested to do so, said the witness, whose name was not disclosed.

The defense has sought to portray Manning as a naive but well-intentioned soldier who wanted to show Americans the reality of war in Iraq and Afghanistan.

Defense lawyers also have contended that much of the material Manning is charged with leaking had been available from public sources before the WikiLeaks disclosure.

The prosecution rested last week after five weeks of testimony, some in closed session. The trial is scheduled to end by August 23. - Reuters