Palestinian terror group, Hamas, which is based in Gaza on Sunday executed a member who allegedly gave Israel the hideout of Mohammed Deif, leader of the group’s military wing,  during 2014’s Operation Protective Edge.

Hamas announced that they executed Mahmoud Eshtewi because of what they dubbed offenses of conduct and ethics. The nature of the offense was not given, but it is likely that Eshtewi was suspected of collaborating with Israel.

Eshtewi, a well-known commander from the eastern Gaza neighborhood of Zeitoun, was a battalion commander of the Hamas military wing. Eshtewi was arrested over a year ago as part of the investigation inyothe attempted targeted killing of Deif. During his lengthy detention, his family held several protests in front of the house of Ismail Haniyeh, deputy political leader of the group, until they were attacked by Hamas security forces.

This is a family that has had deep historic roots in the military wing of Hamas ever since its inception. Ashtiwi began a hunger strike during this detention. The execution was the first time that the military wing of Hamas publicly announced such a proceeding against one of its own members.

During Operation Protective Edge, Israel launched several missiles at a house in Gaza City’s Sheikh Radwan neighborhood in which Deif was believed to be holing up. Hamas claimed that the attack, which killed Deif’s wife and son, was a breach of the ceasefire between the two sides.

Israeli officials have confirmed that the Dief was targeted but declined to speculate on whether he had been injured in the attack. To this day, his fate remains murky, and Hamas insists that the master terrorist is alive and well.

Hamas said in a short Twitter statement that Eshtewi was killed after he confessed. It said the decision to kill Eshtewi, who was detained in January 2015, was taken by its “military and religious judiciary,” a previously unheard-of department.

Deif survived four previous assassination attempts that left him crippled. In 2001, Israel tried to eliminate Deif for the first time, but he escaped and survived. A year later, the second attempt was made: an IDF Apache helicopter fired two missiles at the Deif’s car. One of them hit a vehicle and Deif was wounded in the head and in other places, and went through a rehabilitation process underground.