In explanation for jailing of three men, Mohamed Nagy Shehata says devil encouraged them to use journalism against Egypt

The judge who sent three al-Jazeera English journalists to jail in Egypt has accused them of being in league with the devil in a 57-page explanation of his verdict.

Judge Mohamed Nagy Shehata sentenced Mohamed Fahmy, Peter Greste and Baher Mohamed last month to between seven and 10 years in jail on charges of aiding terrorists and falsifying news. At the time, diplomats and rights observers described the charges as baseless, the process as flawed and the trio's jailing as an attack on free speech.

In his first statements since the trial, Shehata said "the devil encouraged them to use journalism and direct it towards actions against this nation".

He claimed the journalists had doctored footage by "collecting audio and visual recordings and editing them by removing parts and adding it to [footage of] different events". He said this "served the interests of one of the banned terrorist groups [the Muslim Brotherhood], by showing the country – contrary to the truth – in a situation of chaos and upheaval, [and] by portraying it as a lost country suffering from division and internal fighting".

None of the footage shown in court corroborated claims that al-Jazeera English had falsified its reports. Some of it was not even made by al-Jazeera.

A rights campaigner who observed each session of the trial on behalf of Amnesty International said the ruling showed the court had the hallmarks of an inquisition. "When you read the ruling, you realise you don't have a court as much as you have an inquisition," said Mohamed Lotfy, the executive director of the Egyptian Commission for Rights and Freedoms. "It is censoring certain opinions and broadcasted materials because it feels it isn't in the interest of the country and because it threatens national unity. It's a form of censorship."

Fahmy's family criticised the verdict, arguing that it was further evidence of a politicised process.

"What's written in it is an absolute joke," said Adel Fahmy, Mohamed's brother and spokesperson. "When you read this lengthy document, which I did twice, you realise that [the defendants] did not even have a fighting chance. It was all predetermined that this would be the verdict from day one of their arrest. [The judges] have no way of justifying their standpoint, but they're using their authority to say: 'That's that.' It refers to state security's 'secret investigation' without elaborating on what it said. As if to say: 'Just take our word for it.'"

Greste and Baher Mohamed are being held in the same prison wing as the sons of the ousted dictator Hosni Mubarak. Fahmy, the Canadian-Egyptian bureau chief, is in a prison hospital for treatment to a damaged shoulder. All three are expected to appeal their verdicts, a process that could take months.

Hopes of a presidential pardon receded after Egypt's new head of state, Abdel Fatah al-Sisi, declined to intervene the day after their conviction. A few days later, he told Egyptian editors he wished the jailed journalists had been deported rather than arrested, raising hopes of an intervention further down the line.

• Additional reporting by Manu Abdo