U.S. Navy SEALs described their retired platoon leader, who had been demoted from the Navy and then pardoned by President Donald Trump, as "evil", "toxic" and "perfectly OK with killing anybody that was moving", in video footage obtained by the New York Times.

Former Special Operations Chief Edward Gallagher was acquitted by a military jury in July of murdering a captured and wounded ISIL fighter in Iraq by stabbing him in the neck, but found guilty of taking photos with the detainee's corpses. The latter decision was reversed by Trump despite strong objections from Pentagon officials.

In the leaked video, members of Gallagher's SEAL Team 7 Alpha Platoon are shown speaking to agents from the Naval Criminal Investigative Service about their former leader's conduct.

The SEALs described how their chief seemed to love killing, how he targeted women and children and boasted that "burqas were flying."

The footage provides revealing insights of the men who worked with Gallagher and turned him in. They have never spoken publicly about the case, which has divided an elite fighting force which is known for its secrecy. 

"The guy is freaking evil," Special Operator 1st Class Craig Miller said about Gallagher in one interview. 

"The guy was toxic," Special Operator 1st Class Joshua Virens, a sniper, said in another. 

Special Operator 1st Class Corey Scott, a medic in the platoon, said, "You could tell he was perfectly OK with killing anybody that was moving.” 

The material also includes thousands of text messages that the SEALs sent to one another about Gallagher's case and video from a SEAL's helmet camera that shows Gallagher approach a barely conscious captive – a teenage ISIL fighter – in May 2017, according to AP reporting. The camera then shuts off. 

In video interviews, three SEALS said they saw Gallagher go on to stab the sedated captive for no reason and hold an impromptu ceremony over the body as if it were a trophy.

Miller called it "the most disgraceful thing I've ever seen in my life".

Trump's intervention in the case could "potentially damage the integrity of the military judicial system, the ability of military leaders to ensure good order and discipline, and the confidence of U.S. allies and partners who host U.S. troops," U.S. Defense Secretary Mark Esper and other senior military leaders had told the president.

Esper told reporters in early November – before the pardon – that he and the president had had a "robust" conversation. "I offered – as I do in all matters – the facts, the options, my advice, the recommendations," he said.

The White House said later in a statement that the decision was in line with a long history of granting individuals a second chance. 

"The President, as Commander-in-Chief, is ultimately responsible for ensuring that the law is enforced and when appropriate, that mercy is granted," the statement read.

Trump ordered the Navy to allow Gallagher to retire as a SEAL with his full rank intact. That contributed to the firing of Navy Secretary Richard V. Spencer over his handling of the matter.

(With input from agencies)