Cairo, Egypt (CNN) -- Israel's foreign minister Tuesday denied that an American-Israeli law student being held as a spy in Egypt worked for Israeli intelligence. Avigdor Lieberman has no idea why Ilan Grapel, 27, should be detained, he told Israel Radio. Grapel was apprehended Sunday and ordered held for 15 days on suspicion of spying for Israel, said Adel Saeed, a spokesman for Egypt's general prosecutor. Grapel was taken into custody in a five-star hotel in downtown Cairo, Saeed said Sunday. Grapel's mother said he had been staying at a $9-a-night youth hostel. Israeli diplomats visited Grapel on Tuesday, according to Egypt's Israeli embassy, and found him to be in good health. Israel continues working for Grapel's release, the embassy said.
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NEW: Israeli diplomats visited Ilan Grapel on Tuesday
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The aid agency Ilan Grapel was working for says it had no reason to be suspicious
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Foreign Minister Avigdor Lieberman says he has no idea why Grapel was detained
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The law student and former Israeli paratrooper was apprehended and questioned Sunday
His goal was to foment chaos between the @placeholder people and the military, Saeed said.