Sam Kiley, foreign affairs editor for Sky News, has joined a growing chorus of voices calling for the release of five Al Jazeera journalists detained without charge in Egypt.

"My appeal would be to the Egyptian state and the state apparatus ... that is focusing very much on denying debate and freedom of speech in a country that ought to be leading the Middle East and the Arab world culturally and politically," Kiley said at a news conference in London.

The event in the UK capital was hosted by Al Jazeera English, which called on Egyptian authorities to immediately free the journalists.

Correspondent Peter Greste and producers Mohamed Fahmy and Bahar Mohammed were detained in Cairo on December 29, accused of spreading lies harmful to state security.

Two journalists from sister channels Al Jazeera Arabic and Al Jazeera Mubasher Misr - Abdullah Al Shami and Mohamed Bader - have been in detention for five months.

Al Jazeera denies the allegations against its journalists and has condemned their continuing detention.

Greste's appeal against his ongoing detention was denied in a Cairo court on Wednesday.

Source: Al Jazeera