As Benjamin Netanyahu prepares to make a highly controversial speech to the US Congress, the Israel Defence Forces are investigating leaked footage which appears to show soldiers setting dogs on a Palestinian teenager.

The video was taken in December in the West Bank settlement of Carmei Tzur, but gained attention after being posted on Facebook by ultra-nationalist politician Michael Ben Ari, who said of the footage: “The soldiers taught the little terrorist a lesson!” It was quickly removed from his page, according to 972.

The video, which some people may find distressing, shows 16-year-old Hamzeh Abu Hashem cowering and screaming in distress as dogs bite at his clothes. Israeli soldiers hold him throughout the attack and a man can be heard saying "yofi", which means "good".

According to a translation by Israeli newspaper Haaretz, a man can also be heard in the background asking “who’s a chicken?”. Abu Hashem’s father told the newspaper that his son had been arrested on 23 December last year for throwing stones and was treated in hospital for dog bites before being transferred to prison, where he remains.

"We, his mother and I, watched the video, and we couldn't believe what we were seeing," he said. "My wife almost fainted. I don't know if there's a mother or father in the world who can be indifferent to such pictures. It pained us very much, especially the fact that the boy was helpless and the soldiers rejoiced over him."

The IDF said in a statement they had ordered an “internal inquiry” into the footage, adding: “Conclusions will be drawn and the necessary steps will be taken to prevent such incidents from recurring”.

However Israeli human rights group B’Tselem, which drew attention to the use of dogs during the arrest two months ago, said that the footage was an example of “standard” army practice.

"Based on B’Tselem’s experience, this footage is yet another example of the army’s standard practice when dogs are used in arrest operations: a dog handler takes the dog off the leash, the dog chases a group of civilians, clamps its teeth onto a person who did not manage to escape, and holds on until the handler arrives. In some cases documented by B’Tselem, the dog refused to release the person and the dog handler had to use a taser to release his grip," they said.

“Also, two dog handlers from the Oketz unit who took part in this incident had helmet cameras on, and the footage captured on them was presumably available to their commanders during the routine debriefing held after such operations.”