CAIRO: Hundreds of protesters stormed the headquarters of Egypt's widely feared State Security Investigations agency and began sifting through thousands of potentially inflammatory documents, marking another step in dismantling the administration of Hosni Mubarak.

State Security was responsible for suppressing domestic political dissent, as well as for internal counterterrorism, and had a reputation for torturing detainees. The documents could provide a trove of information for cases against the Mubarak government, from the former president down, and could be explosive if publicised, analysts said.

Former Egyptian president Hosni Mubarak was froced out last month. Credit:Reuters

''This could be bigger than Mubarak's fall in terms of the effect it could have on the country,'' said Elijah Zarwan, a Cairo-based analyst with the International Crisis Group.

State Security also collaborated with the US on counterterrorism and was likely to have kept files on the rendition program under which terrorism suspects from around the world were sent to Egypt by the US, Mr Zarwan said.