The grim conditions endured by thousands of people jailed by Egypt’s new military government have been revealed in footage smuggled out of one of the country’s maximum security prisons

The grim conditions endured by thousands jailed by Egypt’s new military government have been revealed in a “through the keyhole” tour filmed by a prisoner.

Footage shot inside a maximum security prison shows inmates crammed into cells so small that personal belongings have to be nailed to the walls to make room on the floor

Squalid, dungeon-like chambers designed for solitary confinement are used to accommodate up to three prisoners at a time, who have to eat and sleep amid insect infestations and sewage

The footage also includes graphic accounts of torture given by people detained during the recent crackdown by the military-led government, which ousted the democratically-elected president, Mohammed Morsi, last summer.

Since then, the government has outlawed Mr Morsi’s Muslim Brotherhood movement as a terrorist organisation, and conducted mass arrests of its supporters

 The authorities have also incarcerated journalists, including several working for Al-Jazeera television, which they regard as overly sympathetic to the Brotherhood and whose Egyptian channel they have banned. The family of one of them, Peter Greste, an Australian, have led a campaign for their freedom. The channel insists its reporters have simply been doing their jobs, pointing out that until last year, the Brotherhood was a legitimate political party.

The “through the keyhole” tour shows inmates living in a breezeblock room described as being no more than six feet long and 4.5 feet wide. The “guide”, who speaks in English, remarks: “This is supposed to be a solitary confinement cell…I do not understand how three people can sleep in here.”

He points out how bags of clothes, bottles of water, blankets and other personal effects are all either hung or nailed to the walls to maximise the available floor space

In one corner is a tiny makeshift kitchen area where inmates can prepare food. It sits right next to a filthy squat-down toilet. A space no more than a few inches high at the top of the cell provides the only light

One inmate, whose name The Telegraph has agreed to withhold for his own security, also tells how he was tortured for four days in a bid to make him confess to what he says were trumped-up terrorism charges

“Throughout those four days they beat me, electrocuted me, they tortured me in ways I can’t describe,” he tells the film. “They started making me memorise confessions, they told me you’re going to have to stand before someone and say what we tell you word for word… Because of all this torture and the threat they made, I told them: ‘I will say whatever you want’.”

The prisoners’ claims are now being assessed by Amnesty International, which says they appear similar to other cases it has documented of Muslim Brotherhood supporters being mistreated.

This is the first time, however, that footage has emerged of prisoners making allegations from within their jail cells. Those who took part appear to have decided that the chance to highlight their plight outweighed the risk of reprisals if they were identified.

Mohammed Elmessiry, Amnesty International’s Egypt researcher, said: “We are still trying to verify these accounts, but they would appear to be in line with other incidents of mistreatment that we have already documented in prisons where both Muslim Brotherhood supporters and liberal activists claim to have been tortured and subjected to electrocution. We call on the Egyptian authorities to investigate these allegations.”

The prisoners’ footage is part of a dossier being compiled by a firm of London-based solicitors acting for Mr Morsi’s Freedom and Justice Party, the political arm of the Brotherhood. They have been passing their information to both the International Criminal Court at the Hague and to Scotland Yard, in the hope that they may seek international arrest warrants against officials thought to have been involved or complicit in torture.

Tayab Ali, a partner with the firm, Irvine Thanvi Natas, said: “As is clear from the footage, the standards in the jail are clearly below anything that could be described as acceptable, yet typical of the conditions that the regime is placing political prisoners in.

“We now also have very firm and concrete evidence of acts of torture being carried out to secure confessions of criminal acts.”

Some Egyptian officials privately admit that the standard of prisons is a disgrace. However, among the effects of last summer’s coup has been to strengthen the hand of the ministry of the interior, which runs them.

In August, 37 prisoners died in an overcrowded prison van which had been left in the summer sun for six hours and was attacked by police with tear gas when the inmates inside tried to get out for air.

Sohair Younis, press spokesman for the Egyptian embassy in London, declined to comment without more details of the particular cases. She conceded that there may be insufficient space for all those held in prison but added: “We don’t torture our prisoners.”

She added: “A lot of money is being spent by some governments on trying to distort the image of Egypt.”