Lebanese television has broadcast footage of what it says is Israeli pilot Ron Arad, missing since he was shot down over Lebanon in 1986.
Ron Arad disappeared after being shot down in 1986
The grainy clip, aired on LBC TV network, shows a bearded man bearing a close resemblance to Maj Arad and reportedly speaking Hebrew.
The video is part of a documentary, due to be shown on LBC next week.
The Israeli government says it believes Maj Arad is still alive but does not know his whereabouts.
The brief clip was repeatedly shown on television in Israel, where Maj Arad's fate has been the source of speculation for 20 years.
Israeli media quoted Maj Arad's family as saying they believed the footage was authentic.
Israeli television producer Naftali Glicksberg, who helped make the documentary, said the Lebanese producers refused to divulge the origins of the film, but that he believes it to be genuine.
"He's speaking Hebrew, and I think this is authentic material," Mr Glicksberg was quoted as telling Israeli Army Radio.
"This doesn't just look like him, this is a soundtrack of an [Israeli] speaking - this sounds like Ron Arad. I believe this is indeed he."
Mr Glicksberg said he believed the footage was shot before December 1989.
Maj Arad was captured by the pro-Iranian Shia militia Amal after bailing out of his aircraft in October 1986.
In 1987 Amal reportedly offered to exchange him for hundreds of Lebanese and Palestinian prisoners, and $3m.
The swap did not materialise and there has been no concrete information about Maj Arad since.