Israel has rejected calls from the United Nations and others for an international investigation of its deadly raid on a Gaza-bound aid flotilla.
Israel says the commandos used force only after activists on board a Turkish flagship attacked them. Nine of the activists were killed.
Israel's military already is investigating the raid.
An official in the prime minister's office says there is "no case in recent history" where a democratic country's army involved in the deaths of civilians in an overseas operation has been subjected to an international investigation.
The official spoke on condition of anonymity pending a formal announcement by the government. He made the remarks on Thursday.
Despite the official's comments, cabinet ministers seem to be in agreement on te involvement of foreign elements in Israel's investigation. Foreign Minister Avigdor Lieberman on Thursday called for the establishment of an Israeli commission of inquiry to investigate the raid.
Lieberman told Ynet the investigation must be supervised by impartial foreign officials.
Industry, Trade and Labor Minister Binyamin Ben-Eliezer announced earlier that he supports the establishment of an international commission of inquiry to probe Monday's calamitous raid, and a source close to Barak said Israel has "nothing to hide, but there is no way of stopping the UN decision to set up a commission of inquiry."
"We operated on the international level to stop the (Gaza) sail, which threatened Israel's security interests. We warned the (flotilla's) organizers and gave them every opportunity; eventually we acted with a lot of restraint in the face of the (activists') violence," the source said.