The Israeli soldier captured by Hamas on Friday has been identified by Israel Radio as Second Lieutenant Hadar Goldin, and media reports described him as a British-born officer in the Givati Brigade.
Israeli media said Lt. Goldin, 23, became engaged to be married just before being sent to Gaza.
It is not clear whether had has duel British and Israeli citizenship, as was reported early in the day. British Foreign Secretary Philip Hammond said the question was being investigated but that so far he had no information to support the reports that Lt. Goldin is a British citizen.
His father, Simha Goldin, told reporters outside their Kfar Saba home after his son went missing that he was "sure the army will not let up for a moment and will turn over every stone in Gaza to bring back Hadar safe and sound."
Haaretz newspaper reported that the father is a historian teaching at Tel Aviv University, where he is a specialist in the history of Ashkenazi Jews.
The Israeli Army said Lt. Goldin and two other soldiers were engaged in destroying a Hamas tunnel east of Rafah on the southern end of the Gaza Strip when Palestinian militants "came out of the ground." One of the militants blew himself up, the army said. A clash ensued and the two soldiers with Lt. Goldin were killed.
In an interview with Israel's Radio Channel 7 last year, Lt. Goldin spoke of how important it was to serve in the Israel Defence Forces.
"Everyone should know how to contribute and dedicate themselves [to the army]," he reportedly said then. "It doesn't have to be in a combat unit, but it should express a sense of burden-sharing, of dedication, of love of one's people – with lots of love, a sense of mission and much sacrifice."
Haaretz said Lt. Goldin has three siblings including a twin brother who was a combat officer serving in Gaza. The brother came home to be with the family after receiving news of his capture, the paper said.
A longtime friend of Lt. Goldin's told Associated Press that he had studied at a religious Jewish seminary in the West Bank settlement of Eli. The friend asked that his name be withheld because he did not have the family's permission to discuss Goldin's personal details with the media.
With reports from Globe wire services