Egyptian photojournalist Mahmoud Abu Zeid won the 2018 Press Freedom Prize awarded by the United Nations cultural agency UNESCO on Monday, a choice that drew criticism from the Egyptian authorities.

The government arrested Abu Zeid, also known as Shawkan, in 2013 as he photographed security forces dispersing an anti-government sit-in, during which hundreds of protesters and several security forces members were killed.

Shawkan, who is still in detention, and more than 700 other people face many charges, which include belonging to the banned Muslim Brotherhood, possessing firearms and murder. If convicted, he could face the death penalty. 

He will have a hearing tomorrow, but no verdict is expected.

He denies all charges, his lawyer Karim Abd el-Rady said. 

International rights organisations, including Amnesty International and The Committee to Protect Journalists, have repeatedly denounced Shawkan's imprisonment and urged the Egyptian authorities to drop charges against him. Amnesty says he was imprisoned merely for doing his job as a photojournalist.

Rights groups say a crackdown by the government of President Abdel Fattah al-Sisi has muzzled freedom of expression after the overthrow of Mohamed Mursi of the Muslim Brotherhood in mid-2013.

"The UN Working Group on Arbitrary Detentions has qualified his arrest and detention as arbitrary and contrary to the rights and freedoms guaranteed by the Universal Declaration of Human Rights and the International Covenant on Civil and Political Rights," UNESCO said on Monday.

Egypt's foreign ministry said in a statement on Sunday that the "nomination of the accused was driven by a number of non-governmental organisations, including organisations dominated by the state of Qatar, which is known for its support and continuous defence of the Brotherhood terrorist group."

"Perhaps you have been following UNESCO, which intends to award a person who is accused of a felony, and which is supported by suspicious organizations and countries known for their support of terrorism," parliament speaker Ali Abdelaal told the state news agency MENA on Monday.

The prize, the Guillermo Cano Press Freedom Prize, will be awarded on May 2 to mark World Press Freedom Day, UNESCO said.

"The choice of Mahmoud Abu Zeid pays tribute to his courage, resistance and commitment to freedom of expression," UNESCO jury president Maria Ressa said in the statement.