The statement on Wednesday said al-Qaida's religious court had decided to hand over Ihab al-Sherif, who was seized in Baghdad on Saturday, to its fighters "to carry out the punishment of apostasy against him".
"The sharia court of the Al-Qaida in Iraq organisation has decided to transfer the apostate ambassador of Egypt, which has allied itself to the Jews and Christians, to the mujahedeen to carry out the punishment of apostasy against him," the statement said.
The statement appeared on the same website which earlier showed photos of al-Sherif's ID cards and also included a speech purportedly by al-Qaida in Iraq leader Abu Musab al-Zarqawi rejecting any moves to end the fight against US and Iraq forces here.
Three days after al-Sherif was seized, gunmen fired at diplomats from Bahrain and Pakistan in what officials
suspected were attempts aimed at isolating Iraq's US-backed government in the Islamic world.
"These embassies are nothing but observation posts to hunt down the foreign mujahedeen by following them, standing in their way and preventing them from communicating with the brothers of jihad and faith in Iraq, Afghanistan and elsewhere," the statement said.
Iraq's Interior Minister, Bayan Solagh, meanwhile said that some foreign diplomats in Baghdad have held meetings with armed groups and that they bear responsibility for their actions.
"We have some information that some ambassadors are meeting terrorists and they bear the responsibility for that," he said.
"We have some information that some ambassadors are meeting terrorists and they bear the responsibility for that"
Iraqi Interior Minister
Asked if he was referring to al-Sherif, Solagh said: "I'm not talking about a particular incident. The Egyptian ambassador went to a hot spot alone and he bears responsibility for that."
Al-Sherif was abducted on the capital's west side after stopping to buy a newspaper.
Iraqi government spokesman Leith Kubba said on Tuesday that al-Sherif's security may have been compromised because of his contacts with political groups close to the insurgency.