Hundreds of Egyptians noisily 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 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 who cannot find work at home.

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

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

This time, the prominent Egyptian human rights lawyer was arrested upon his April 17 arrival in the Saudi port of Jiddah, el-Gezawi's sister told a private 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 Madina, 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. El-Gezawi had earlier filed a lawsuit in Egypt against King Abdullah over the alleged arbitrary detention of hundreds of Egyptians living in the kingdom. A rights group said he has criticized the monarch in television interviews.

The protesters outside the embassy chanted slogans against the Saudi monarch and the kingdom's ruling al-Saud family. Some protesters raised shoes alongside a picture of the king , a sign of deep contempt in the Arab world.

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. Foreign Ministry spokesman Amr Rushdi said Cairo was in constant contact with Saudi authorities over the arrest.

However, he said the ministry would not help feed a media campaign that incites public opinion.

"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."

Lawmaker Mostafa el-Naggar was among several lawmakers who demanded parliament launch an inquiry into the issue.

"Violating the dignity of an Egyptian is an offense to the dignity of the entire nation," he wrote on his Twitter account.

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

The Egyptian media and human rights groups said the doctors had been wrongly blamed for the princess' alleged addiction. They demanded that now-ousted president Hosni Mubarak, who had close ties with the Saudi king and royal family, intervene.

The two were pardoned and later returned to Egypt.