Hundreds of Egyptians protested outside the Saudi embassy on Tuesday to demand the release of an Egyptian human rights lawyer detained in Saudi Arabia for allegedly insulting the Western-backed kingdom's absolute monarch.
Protesters demanding freedom for Ahmed el-Gezawi chanted "Down, down with Al-Saud," referring to the Saudi royal family, and "Screw you, your majesty," in reference to King Abdullah, the Saudi monarch.
The demonstrators called for the expulsion of the Saudi ambassador in Cairo and some raised their shoes alongside a picture of the king, a sign of deep contempt in the Arab world.
The detention of Mr Gezawi has revived long-standing resentment over the treatment of Egyptians working in oil-rich Saudi Arabia, a destination for more than a million Egyptians seeking better jobs.
At the protest a woman cloaked in a black abaya, a long garment worn by many devout Muslim women in Egypt, held a picture of her son and said that he has been detained for two years in a Saudi prison.
The Saudi embassy said in a statement that said Mr Gezawi has not been convicted or sentenced in any case.
Instead it claimed he was being questioned by authorities after airport officials found more than 20,000 anti-anxiety pills hidden inside his luggage.
It also said he was not wearing white pilgrims' clothes, which they said indicated he was not making a religious pilgrimage as his family maintains.
Egypt's foreign ministry said it was closely following the case while several MPs demanded that parliament launch an inquiry into the issue.