The family was also informed that his body was still being held by Hamas militants.
Samarno from Tel Aviv was at the Supernova festival on October 7 along with his friends when the Hamas assault commenced.
According to his family, he attended the festival along with two of his friends.
While the bodies of his two friends were recovered, it was believed that Samarno was held hostage in Gaza.
His family has said that they will hold a ceremony for him later in the day and begin a weeklong mourning period.
During the now collapsed humanitarian pause from November 24-30, 86 Israeli and 24 foreign national hostages had been released from Hamas capitivity.
Authorities believe that 137 people remain captive in Gaza, including Israelis and foreign nationals.
Before the pause, four civilian hostages were released by Hamas, one Israeli soldier was rescued by Israeli forces and three bodies of hostages were retrieved.
On its part, Israel freed 240 Palestinian prisoners, mostly children and women.
More than 1,200 people, including foreign national, have been killed in Gaza since the war erupted on October 7.
IANS