An Egyptian court has sentenced three Al-Jazeera English journalists to three years in prison for broadcasting false news, the last twist in a long-running trial criticised by press freedom activists.

The case against Canadian national Mohammed Fahmy, Australian journalist Peter Greste and Egyptian producer Baher Mohammed embroiled their journalism into the wider conflict between Egypt and Qatar following the 2013 military ouster of Islamist president Mohammed Morsi.

Mr Greste, deported in February, spoke to Al-Jazeera from Sydney and criticised the verdict while Mostefa Souag, Al-Jazeera English acting director-general, said it "defies logic and common sense".

"The whole case has been heavily politicised and has not been conducted in a free and fair manner," Mr Souag said in a statement.

"There is no evidence proving that our colleagues in any way fabricated news or aided and abetted terrorist organisations, and at no point during the long drawn-out retrial did any of the unfounded allegations stand up to scrutiny."

The case began in December 2013 when Egyptian security forces raided the hotel suite used by Al-Jazeera at the time to report from Egypt.

Authorities arrested the trio, later charging them with allegedly being part of Mr Morsi's Muslim Brotherhood, which authorities have declared a terrorist organisation, and airing falsified footage intended to damage national security.

Since Mr Morsi's ouster, Egypt has cracked down heavily on his supporters and the journalists were accused of being mouthpieces for the Brotherhood.

Al-Jazeera and the journalists denied the allegations, saying they were simply reporting the news.

At trial, prosecutors used news clips about an animal hospital with donkeys and horses, and another about Christian life in Egypt, as evidence they broke the law.

Defence lawyers - and even the judge - dismissed the videos as irrelevant.

Nonetheless, the three men were convicted on June 23, 2014, with Mr Greste and Mr Fahmy sentenced to seven years in prison and Mr Mohammed to 10 years.

The verdict brought a landslide of international condemnation and calls for newly-elected president Abdel Fattah el-Sissi, who as military chief led the overthrow of Mr Morsi, to intervene.

Egypt's Court of Cassation, the country's highest appeals court, later ordered their retrial, saying the initial proceedings were marred by violations of the defendants' rights.

Egypt deported Mr Greste in February, though he remained charged in the case. Mr Fahmy and Mr Mohammed were later released on bail.

Human-rights lawyer Amal Clooney criticised the sentences, saying that "everyone has said there is no evidence to sustain any of the charges".

She said: "The verdict today sends a very dangerous message in Egypt.

"It sends a message that journalists can be locked up for simply doing their job, for telling the truth and reporting the news.

"It sends a dangerous message that there are judges in Egypt who will allow their courts to become instruments of political repression and propaganda."

Ms Clooney - who represented Mr Fahmy - added she hoped Egyptian president Abdel Fattah el-Sissi would pardon the three journalists.

Amnesty International called the sentences the "death knell for freedom of expression in Egypt".

Philip Luther, director of Amnesty's Middle East and North Africa programme, said: "The fact that two of these journalists are now facing time in jail following two grossly unfair trials makes a mockery of justice in Egypt.

"Today's verdict must be overturned immediately. Mohamed Fahmy and Baher Mohamed should be allowed to walk free without conditions.

"We consider them to be prisoners of conscience, jailed solely for exercising their right to freedom of expression."