FORT MEADE (USA), July 8: Lawyers for a US Army soldier who gave thousands of classified documents to WikiLeaks opened their defence at his trial on Monday with leaked video of a helicopter attack in Baghdad—footage that portrayed the military in a negative light.

The video is the basis of an espionage charge alleging Bradley Manning had unauthorised possession of US defence information.

Manning has admitted to leaking the cockpit video showing a 2007 attack that killed 11 men, including a Reuters news photographer and his driver. The aircrew can be heard laughing and calling the victims “dead bastards.” Manning has said he was troubled by their behaviour and by the US military's refusal to release it.

The Pentagon concluded that the troops reasonably mistook the journalists for enemy combatants.

WikiLeaks posted it in April 2010 under the title “Collateral Murder.’’

The 25-year-old Manning admitted he leaked the video and hundreds of thousands of classified Iraq and Afghanistan war logs and diplomatic cables while working as an intelligence analyst in Baghdad in 2009 and 2010.

Manning says he leaked the material because he was troubled by what it revealed about US foreign policy.

Manning’s defence team asked the military judge to acquit him of as many as seven charges for lack of incriminating evidence. The government has until Thursday to respond, the judge said.

The defence is seeking acquittal on the most serious charge of aiding the enemy, which carries a possible life sentence; a computer fraud charge and as many as five counts of theft. Details of the motions weren't discussed in court. Manning faces 21 contested counts.

He pleaded guilty in February to reduced versions of some charges. He faces up to 20 years for the admitted offences.

On Monday, the defence called its first witness, Chief Warrant Officer 2 Joshua Ehresman, to establish the wide authorised access Manning and other intelligence analysts had.

Ehresman testified that Manning and other intelligence analysts scoured a classified computer network for bits of information needed by field commanders.

Ehresman said the job meant “pulling everything you can from all intelligence assets.” Manning was “the go-to guy” among the analysts in his unit in Iraq and the most productive worker, Ehresman said.

The 10 prospective witnesses on Monday include Harvard law professor Yochai Benkler, who has written that leaking something to WikiLeaks is no different than leaking it to The New York Times.

Benkler’s testimony could refute the government’s assertion that Manning knowingly gave intelligence to the enemy because he knew Al Qaida members would see what WikiLeaks posted on its website.—AP