Israel will free 20 Palestinian women from jail as early as Friday in exchange for a videotape from Hamas proving an Israeli soldier held in the Gaza Strip since 2006 is alive, officials on both sides said on Wednesday.

Egyptian and German mediators are continuing to work on a final deal to swap the soldier, Gilad Shalit, for hundreds of Hamas prisoners. The negotiations are part of international efforts to ease Israel's blockade of the Hamas-run Gaza Strip.

"It is important for the entire world to know that Gilad Shalit is alive and well and that Hamas is responsible for his well-being and his fate," Israeli Prime Minister Benjamin Netanyahu said in a statement.

Shalit, now 23, was spirited into the Gaza Strip by Islamist militants who tunneled into Israel three years ago in a raid in which two Israeli soldiers and two of the attackers were killed.

An Israeli official said the handover of the 20 women and the tape should take place on Friday, at the end of a two-day period when Israeli citizens can appeal in court against their release, an Israeli official said.

He added that a German mediator had already seen the video and believed it genuinely showed Shalit during recent weeks -- and certainly after Israel's offensive in Gaza in December and January in which some 1,400 Palestinians were reported killed.

The video lasts about a minute, said a spokesman for the Popular Resistance Committees, one of the Hamas allies that took part in the raid in which Shalit was captured.

"It shows Shalit alive and moving," the spokesman, Abu Mujahed, said.

Announcement of the pending exchange was the first major sign of progress in efforts to put together a deal between Israel and Hamas Islamists.

"This is a humanitarian gesture," said an Egyptian security source close to the mediation efforts Cairo has been pursuing.

But an Israeli official cautioned that "lengthy and difficult negotiations" were still ahead before a final deal could be reached.

Public pressure has been mounting on Netanyahu to win freedom for the bespectacled soldier, who also holds French citizenship, in a deal that could involve the release of Hamas militants behind attacks that have killed Israelis.

Palestinians view brethren held in Israeli jails as heroes and a widescale release of prisoners in exchange for Shalit would be a boost for Hamas, an Islamist group opposed to peace with Israel.

Only one of the women, who was to be released along with her child, was from Gaza, Hamas officials said. The other 19 were from the Israeli-occupied West Bank, where Hamas's secular rivals from President Mahmoud Abbas's Fatah party hold sway.

Israeli officials said none of the women had been directly involved in killings and none was serving a sentence of longer than two years.

A spokesman for Hamas's armed wing, Abu Ubeida, told a news conference in Gaza that four of the women to be released were members of Hamas, while five were members of Fatah. Three more were members of Islamic Jihad and the rest from other groups.

Shalit has not been visited by the International Committee of the Red Cross and only a few letters and an audio cassette from him have been sent to his family, which has waged a vocal campaign to get him freed.

Israel holds more than 10,000 Palestinians in its jails. Hamas is negotiating for the release of hundreds of its members. (Writing by Alastair Macdonald and Jeffrey Heller, Additional reporting by Jeffrey Heller and Ari Rabinovitch in Jerusalem, Editing by Mark Trevelyan)