Edward Gallagher could have faced life in prison if found guilty. (File)

A US Navy SEAL platoon leader charged with committing war crimes in Iraq was acquitted by a military jury on Tuesday of murder and all other counts except for unlawfully posing with the corpse of a captive ISIS fighter.

The seven-member jury deliberated for about nine hours before delivering its verdict in the court-martial of Special Operations Chief Edward Gallagher, a decorated career combat veteran whose case had drawn the interest of US President Donald Trump.

The single offense of posing for unofficial pictures with a human casualty, in this case the remains of the Iraqi whom Gallagher was acquitted of killing, carries a maximum sentence of four months imprisonment.

Navy authorities said Gallagher has credit for nearly seven months of time already served in pre-trial custody, so he would presumably remain a free man. A sentencing proceeding was to commence later in the day to determine whether Gallagher faces any other punishment, such as a demotion in rank.

The case went to the jury of five US Marines and two Navy personnel - all but one a combat veteran - as the trial phase of the court-martial entered its third week.

Gallagher could have faced life in prison if found guilty of the most serious charge against him, premeditated murder. Several fellow SEAL team members testified he fatally stabbed the captured Iraqi prisoner in the neck with a custom-made knife after the teenage fighter was brought to Gallagher's outpost for medical treatment.

Some of the same witnesses also said they saw Gallagher, who was originally trained as a medic, perform a number of emergency procedures on the detainee before he died.

Gallagher also was charged with attempted murder in the wounding of two noncombatants - a schoolgirl and an elderly man - shot from a sniper's perch, as well as with obstruction of justice and other offenses.

He was found not guilty of all charges but the one stemming from the photos he and fellow SEAL team members took with the dead ISIS fighter, who was badly wounded in an air strike.

Gallagher, 39, a platoon leader, has steadfastly professed his innocence, insisting that disgruntled subordinates with no prior battlefield experience fabricated allegations against him over grievances with his leadership style and tactics.

Trump intervened in Gallagher's case months ago, ordering he be moved from pretrial detention in a military brig to confinement at a Navy base. The presiding judge later released Gallagher from custody altogether.

The chief petty officer was arrested in 2018, more than a year after returning from his eighth overseas deployment in Mosul, in northern Iraq.