A former Egyptian lawmaker went missing nearly three weeks ago and may have been detained by security forces, his wife said in a request sent to authorities seeking her husband's whereabouts.Rights activists say Egyptian authorities have disappeared dozens of people in recent years, part of a wide-ranging crackdown on dissent launched after the military overthrew President Mohammed Morsi, an elected but divisive Islamist president, in 2013.President Abdel-Fattah al-Sisi's government dismisses as unfounded accusations that it disappears its critics, arguing that in many cases the disappeared left their families to join Islamic militants fighting security forces in the north of Egypt's Sinai Peninsula.Shaymaa Afifi, the wife, said in her request obtained by The Associated Press on Wednesday that Mustafa el-Nagar, 38, went missing on September 27 while traveling to the southern city of Aswan.She said an unknown person informed her by telephone last week that police arrested her husband but gave her no further details.Egypt's main appeals court on Monday upheld a three-year prison sentence for el-Nagar and some two dozen people, including Morsi, following their conviction of insulting the judiciary.El-Nagar had been out on appeal. His wife said he had been expected to attend Monday's hearing at the Court of Cassation but he did not show up.Another activist, who was a member of the pro-democracy April 6 Movement, was arrested on Sunday, his wife said.Heba Anees told the AP on Wednesday her husband, dentist Walid Shawki, was taken by three policemen in plain clothes from his private clinic in Cairo. She said the family does not know where he is being held.She said officers at the nearest police station denied any knowledge of her husband's detention. The family later learned he was being held by National Security, an arm of the Interior Ministry focused on perceived threats to the state.Both men's families have sent requests to prosecutors and the Interior Ministry, which supervises police, asking for information about their whereabouts. A spokesperson for Egypt's Interior Ministry did not respond to multiple requests for comment.The April 6 Movement played a key role in organising the 2011 uprising that forced longtime autocrat Hosni Mubarak from power. It was banned by court order in 2014, accused of illegally receiving foreign funds and threatening national security. Its leaders have all been jailed or fled the country, and the rest, like Shawki, have largely gone silent.Egypt has arrested thousands of people since 2013, mainly Islamists but also a number of secular activists. Many have been held for months or years without charge.Human Rights Watch, citing figures from independent Egyptian rights campaigners, said earlier this month that authorities have disappeared at least 230 people since August 2017 and are increasingly targeting journalists and rights activists. * Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.