Hamas leader Moussa Abu Marzouq blamed Israeli Prime Minister Benjamin Netanyahu on Thursday, for what he said was a delay in the release of Israeli and Palestinian prisoners in a swap deal.

Citing Netanyahu's "intransigence," the official said the leader bore "full responsibility" for the continued confinement of captured Israeli soldier Gilad Shalit as well as thousands of Palestinians considered prisoners of war.

A return to German mediation, he said, would be "impossible," but welcomed efforts from other parties that could secure the release of the detainees, noting in particular the importance of Egypt in any deal.

"Whatever international side enters the role of mediator, Egypt must be involved," he said, adding also that it would not be possible to "start at point zero," in any deal.

Previous negotiations had Hamas dealing on behalf of the factions which abducted Shalit in a 2006 cross-border raid as he was on patrol near Gaza. In exchange for his release Hamas has asked for the freedom of 1,000 Palestinian political prisoners, including a list of 450 named individuals and another 350 left to Israel's discretion.

The list includes elected Palestinian officials, militant leaders, the elderly, the sick, long-term prisoners, women and members of the Palestinian leadership. Israel says a large portion of those named have "blood on their hands," and either refused their release entirely, or suggested they be released into exile abroad.

Officials refused the suggestion of forced exile, and a deal has not been struck.