An Israeli rights group has released a video of the moments preceding the deadly shooting of a Palestinian teenager, claiming the clip is evidence the boy was shot in the back when fleeing.

Left-wing NGO B'Tselem said the footage contradicts the official account of the incident, according to which Israeli Defense Forces (IDF) Colonel Yisrael Shomer opened fire on Mohammad Kosba as he felt threatened after the 17-year-old threw a rock at his vehicle.

Kosba, from the occupied West Bank village of al-Ram, was killed earlier in July near the Qalandiya checkpoint, south of Ramallah.

He can be seen in the security camera video from a nearby gas station charging an IDF vehicle and hurling a stone at it, before running away – swiftly chased by soldiers.

The IDF initially said several Palestinians were throwing stones at the vehicle and Shomer shot back feeling his life was in danger.

"The forces called the suspect to halt and shot warning shots in the air. Once he continued hurling rocks at close range and in response to the imminent danger, the forces fired towards the suspect," an IDF spokeswoman told AFP after the incident.

B'Tselem said the video and forensic evidence suggest this was not the case. The group claimed that, according to its investigation, Kosba died from three bullet wounds to his upper body, including two at the back.

"The claim that Kosba posed a mortal threat to the soldiers at the time of the shooting, having fled the scene, is unreasonable," B'Tselem said.

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

The group also quoted eyewitness as saying the officer failed to provide first aid to the teenager, leaving the scene just after the shooting.

"Col Shomer shot Ali-Kosba from a distance of some 10m and then went up to him and moved him with his leg. Then, instead of obtaining medical aid for the injured youth, the soldiers drove off," the group said.

The IDF has not commented on the video but after this emerged, Shomer was questioned by the its criminal investigation unit, The Times of Israel reported.