Israel's Mossad spy agency said on Thursday that it had brought home the watch of an Israeli agent executed in 1965 while working deep undercover in Syria.
Eli Cohen was tried and hanged for espionage by the Syrians after he had successfully infiltrated the top levels of the Syrian regime.
"The Mossad returned to Israel the wristwatch of the late Mossad fighter Eli Cohen," an Israeli government statement said.
"The wristwatch was returned in a special Mossad operation which took place recently," it added.
"After Eli Cohen's execution on 18 May 1965, the wristwatch was held by an enemy state," it added.
"Upon the watch's return to Israel, special research and intelligence operations were carried out which culminated in the unequivocal determination that this was indeed Eli Cohen's watch."
It did not elaborate.
"The moment that they informed me my mouth went dry and I got the chills," Eli Cohen's widow Nadia told Mako commercial Israeli TV channel.
"At that moment I felt that I could feel his hand, I felt that part of him was with us."
Syria, which has never signed a peace treaty with Israel, has failed to respond over the years to Israeli requests to repatriate Cohen's remains on humanitarian grounds.
Pleas sent in 2004 by then Israeli president Moshe Katsav, were passed to his Syrian counterpart Bashar al-Assad by French, German and United Nations envoys.
The information Cohen obtained was seen as playing a key role in Israel's conquest of the Golan Heights from Syria in the 1967 Six-Day War.
"This year, at the conclusion of an operational effort, we succeeded in locating and bringing to Israel the wristwatch that Eli Cohen wore in Syria until the day he was captured," Thursday's statement quoted Mossad chief Yossi Cohen as saying.
"The watch was part of Eli Cohen's operational image and part of his fabricated Arab identity."
It said that the watch would be placed on display at Mossad headquarters until the Jewish New year in September and would then be presented to Cohen's family.
In the statement Prime Minister Benjamin Netanyahu paid tribute to Cohen and to his successors at the Mossad.
"I commend the fighters of the Mossad for the determined and courageous operation, the sole objective of which was to return to Israel a memento from a great fighter who greatly contributed to the security of the state," he said.