JERUSALEM, March 11 -- The father of an Israeli who was executed by the Islamic State (IS) denied on Wednesday the group's allegations that his son was an agent of Israeli Mossad spy agency.

The IS published a video on Tuesday of the execution of Muhammad Musallem, a 19-year-old Arab Israeli from east Jerusalem, who had joined the IS in 2014. In the video, Musallem said he was an Israeli spy.

However, his father Said told the Israeli Army Radio that he believes his son was coerced to the confession, saying Muhammad was probably executed after trying to leave the group.

"Mossad? What Mossad? Would Mossad enlist a 19-year-old boy who doesn't know the first thing about life?" Said told the radio.

Regarding the reason his son left for Syriafour months ago and joined the group in the first place, he said the group probably made him "promises of paradise and money" and "brainwashed" him.

The father said the group probably executed his son after he witnessed the group's tactics and had recently tried to cross the border into Turkey.

"He was actually against Daesh (the Arab name for the Islamic State), he told his brother 'don't believe anything you see on television'," Said told the radio.

The video posted by the Islamic group on Tuesday ran for 13 minutes and was taken off from the YouTube website shortly after its publication.

Israel's Foreign Ministry refused to comment on the report of Musallem's death. The Shin Bet Security Agency announced earlier this year that the 19-year-old had left to fight with the IS.