A key suspect in the assassination of former Lebanese Prime Minister Rafik Hariri has been arrested in Dubai. Mohammed Zuhair al-Siddiq, a former Syrian intelligence officer, was detained on Sunday. Mr Siddiq was a witness to Hariri's killing, but an international arrest warrant was later issued for him. There is widespread suspicion inside and outside Lebanon that Syria was involved in Hariri'S death in 2005, though Damascus denies this strongly.