Hundreds of Egyptians protested outside the Saudi Embassy on Tuesday demanding the release of an Egyptian human rights lawyer detained in Saudi Arabia for allegedly insulting the kingdom's monarch.

The incident surrounding Ahmed el-Gezawi has revived long-standing resentment over the treatment of Egyptians working in the oil-rich kingdom, which is a destination for more than a million Egyptians searching for better jobs.

It also raises questions about whether the Egyptian government does enough to protect its citizens or, as many activists claim, curbs its criticism so as not to alienate the wealthy kingdom or endanger Egyptian jobs there.

The Saudi Embassy in a statement said el-Gezawi has not been convicted or sentenced in any case. Instead they said 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.

Protesters chanted, "Down, down with Al-Saud!" referring to the Saudi royal family and "Screw you, your majesty!" in reference to King Abdullah, the aging Saudi monarch. The demonstrators called for the expulsion of the Saudi ambassador in Cairo, and some raised their shoes alongside a picture of Abdullah, a sign of deep contempt in the Arab world.

Anti-Saudi sentiment has flared in recent years following reports of Egyptian nationals being mistreated in the kingdom or experiencing a miscarriage of justice in a Saudi court.

In this incident, a prominent Egyptian human rights lawyer was arrested upon his April 17 arrival in the Saudi port of Jiddah, el-Gezawi's sister told an Egyptian television channel Monday.

El-Gezawi flew to Jiddah on his way to perform a minor pilgrimage, called umrah, to Islam's holy shrines in the Saudi cities of Mecca and Medina, said Shereen el-Gezawi. The fact that he was arrested on his way to perform a religious rite further enflamed Egyptian sentiment.

El-Gezawi's sister said he had been convicted in absentia and sentenced to a year in prison and 20 lashes by a Saudi court for insulting the king. However he was not notified of the court's ruling ahead of his Saudi trip. El-Gezawi had earlier filed a lawsuit in Egypt against King Abdullah over the alleged arbitrary detention of hundreds of Egyptians.

A partner at el-Gezawi's law firm, Mohammed Nabil, said in recent years they have filed lawsuits concerning 34 cases of Egyptians held in Saudi detention without a stated reason or legal recourse.

As Arab uprisings have toppled four longtime Middle Eastern rulers, Saudi Arabia has been worried of signs of rebellion within its borders. Attempts to advocate for more rights, as el-Gezawi has done, or question the authority of the monarchy in any way, have been met with strong opposition by authorities.

Egypt's foreign ministry said it was closely following the case but warned people not to get too carried away with their anti-Saudi protests. Spokesman Amr Rushdi said Cairo was in constant contact with Saudi authorities over the arrest but said the ministry would not help feed a media campaign that incites public anger.

"Citizens should think about how they voice their views and whether they would serve the interests of the detained citizen or make it worse," he said. "This is not a football match."

Several lawmakers demanded parliament launch an inquiry into the issue.

At the protest, a woman cloaked in a black abaya, a long garment worn by many conservative Muslim women in Egypt, held a picture of her son. She said he's been detained for two years in a Saudi prison.

"This is my 48th sit-in over the past two years. No one listens, no one sees, and no one talks about the Egyptians' rights," she said. She did not want to be identified because her conservative family frowns on women demonstrating publicly.

In 2008, another case caused a public uproar, when two Egyptian doctors were sentenced to seven years in prison and 700 lashes each for allegedly selling illegal pharmaceuticals and driving a Saudi princess to drug addiction.

Local media and rights groups said the doctors had been wrongly blamed for the princess' alleged addiction.

The two were pardoned and later returned to Egypt.