Warning: You may find some of the footage disturbing.
Egypt's jails were one of the most feared parts of former President Hosni Mubarak's security apparatus - and one of the reasons for the uprising that took place in 2011.
But human rights groups are increasingly documenting a return to some of that period's worst abuses.
Since July 2013, thousands of Egyptians have been rounded up and jailed - many held without charge or judicial oversight, in prisons where they can face torture and mistreatment.
Inside Egypt's Prisons is a special investigation by Al Jazeera correspondent Jamal Elshayyal with exclusive interviews with former detainees.