Gas station security camera footage that appears to show a Palestinian teenager running away from soldiers just moments before he was fatally shot has cast further doubt on a high-ranking Israeli army officer's claim that he acted according to protocol and only opened fire when faced with mortal danger.

The video acquired by B'Tselem, an Israeli human rights group, purports to show 17-year-old Mohammed Kusbah throw a stone from close-quarters at the army officer's staff vehicle as it approaches a junction, breaking the windshield.

The car the screeches to a halt and two soldiers jump out pursuing the youth out of the camera's view, before moments later they return and drive off. It is in these unseen intervening seconds that Kusbah is killed.

According to the initial account of Col. Israel Shomer after the July 3 incident, which occurred at a junction near Qalandia checkpoint in the West Bank, he fired the fatal shots in self-defense after his troops came under a hail of stones and rocks.

However, multiple eyewitness testimonies gathered by B'Tselem and journalists suggest that the officer shot at the teenager as he ran away from him. Medical records obtained by the Guardian that show Kusbah was shot in the back and side of the head lend further to weight to these accounts.

Witnesses to the incident also claimed that Shomer then "pushed" or "kicked" the fatally wounded teenager with his foot as he was dying on the floor, and that the soldiers then left the scene without providing any medical assistance.

'He could have arrested him, he could have shot him in the leg, but he wanted to kill him.'

While Israeli military guidelines permit the use of live ammunition during arrests, rounds cannot be fired at the upper body.

B'Tselem said its investigation published on Sunday had found that the killing was "unjustified and unlawful" and that the "official version presented did not accord with the facts of the incident."

"There is no doubt that the shattering of the jeep's front window with a stone endangered the passengers when it happened. However, Kusbah was shot in the back after the fact, when he was already running away and posing no 'mortal threat' to the soldiers," the NGO said in a statement. "Feeling a sense of danger is not enough to justify any action."

Stone throwing came to be a common form of guerrilla protest among Palestinian youths during and following the First Intifada. At least 14 people have been killed as a result of hurled rocks and Israeli vehicles are frequently targeted in tense areas.

While senior figures in the Israel Defense Forces initially offered their backing to Shomer following the release of the video, the officer has been brought in for questioning according to the Times of Israel.

Thaer Kusbah, the brother of the killed teenager, suggested that Shomer's actions were deliberate. "It's clear that Mohammed threw a stone, and the officer came out of the car. He could have arrested him, he could have shot him in the leg, but he wanted to kill him," he said.

During the Second Intifada two of Thaer's brothers, aged 11 and 15 years old, were reportedly killed by the Israeli military.

The Associated Press contributed to this report.