An Israeli air force navigator shot down over Lebanon 17 years ago and captured is probably still alive, family members said Tuesday, quoting a secret government report on his fate.

A news conference Tuesday by the family of the navigator, Ron Arad (search), came amid reports that negotiations for a prisoner swap between Israel and the Lebanese guerrilla group Hezbollah (search) did not include Arad.

The government permitted members of Arad's family to see the top-secret report last week.

Arad's brother, Chen, said it shows that authorities determined at different points in recent years that Ron Arad was still alive, though he has not been heard from in more than a decade. Arad would now be 45 years old.

"The report concludes that the likelihood that Ron is alive is greater than any other possibility," Arad said. The document also speculates about his captors and where he is being held, he said.

"The address is Iran," Arad said, refusing to give details, saying he wanted to protect the identity of the source of the information in the report.

Israeli officials refused to comment.

Israeli media have reported that the document — kept under wraps because of its sensitive contents — concluded that the Israeli defense establishment should act on the assumption that Arad is alive.

Ron Arad's plane was shot down over south Lebanon in 1986. The pilot was rescued, but Arad was captured.

His captors released a picture of him a year later, and a single letter from Arad arrived by way of the International Red Cross, but no signs of life have been seen since then.

In a prisoner swap in the works between Israel and Hezbollah, Israel would free several hundred Arab prisoners, including Palestinians, in exchange for Israeli businessman Elhanan Tannenbaum (search) and the bodies of three soldiers abducted by Hezbollah in 2000.

Among those freed by Israel would be two Lebanese guerrilla leaders, Abdel Karim Obeid and Mustafa Dirani, whom Israel snatched in 1989 and 1994, respectively, as bargaining chips for the release of Arad.

Israelis say Dirani personally held Arad for a time before turning him over to a Lebanese group. The Arad family objects to Dirani's release unless Arad is part of the deal.