The investigation into last week's terror attacks on London widened on Friday when Egyptian authorities confirmed the arrest of a chemist wanted in connection with the discovery of a bomb factory in northern England.

British intelligence officials are working with their Egyptian counterparts in an investigation which became public on Friday when the interior ministry in Cairo confirmed that Magdy Mahmoud Mostapha al-Nashar, a 33-year-old Egyptian who trained as a biochemist in the UK and US, was being interrogated.