Corporal Zion Tayeb was listed as missing in action in the immediate aftermath of a battle with Syrian commandos who stormed the position he manned on Mount Hermon in the 1973 war. It was months later that the army said his body was found and positively identified, along with the bodies of five other soldiers, Xinhua reported.
In the years since then, however, Tayeb's family challenged the authorities' claim that he was buried at the Mt. Herzl military cemetery in Jerusalem, instead contending that he was taken as a prisoner of war and that efforts to discover his fate were not exhausted, Israel's Army Radio reported on Sunday.
According to the station, which broke the story, the family has previously taken legal action against the military in its bid to discover the truth. A month ago, the Supreme Court rejected their petition to exhume the remains in order to conduct a DNA test.
Accompanied by a pathologist, the family dug up the gravesite, and discovered an empty casket.
"They didn't believe it, and thought it may have been a mistake," Shlomo Rahavi, the attorney representing the family, told Israel's Channel 10. "How is it possible that throughout 40 years, the family has received mistaken information from the defence ministry in the best case, or been misled in the worst case?"
Rahavi said the discovery, which came a day before Israel was set to pay tribute to its fallen soldiers, marked "a new battle" for the family.
"It's still early to try and understand what happened. The family has just received confirmation of its fears -- that her son was not killed as was claimed the entire time," he said.
The family would seek a state-appointed committee to probe the case, "and find answers to both old and new questions", Rahavi added.
Army Radio said the defence ministry has opened an investigation, and quoted ministry sources who said they were examining the veracity of its report.
In a statement, the military said that the family's request to unearth the grave was examined by the Supreme Court, which accepted the state's position that the body was identified and dismissed the petition to exhume the remains.
"The IDF pays its condolences to the family and will continue to accompany it as much as necessary," the statement said.