On Wednesday, a video was published of Mr Aslin and Mr Pinner sitting on an airline, in which Mr Pinner said that their release was made "by the skin of our teeth”.

They also said they are “now out of the danger zone and we're on our way home to our families”. 

Liz Truss, the Prime Minister, confirmed that the release of the five Britons had been secured by working with Ukrainian authorities and the Crown Prince of Saudi Arabia Mohammed bin Salman. 

The non-profit organisation Presidium Network, which has been supporting the family of Mr Healy, said the men had landed "safely" in the UK and had been reunited with their families.

Dominik Byrne, co-founder of the organisation, said: "We don't know exactly if they've all returned back to their homes yet, but we do know they're with families at the moment."

The Foreign, Commonwealth and Development Office has not commented on the whereabouts of the ex-prisoners.

Mr Aslin's release was confirmed by his local MP Robert Jenrick, while multiple reports also indicated that Mr Pinner would also be returning home. 

Mr Jenrick said he was "deeply grateful" to the Ukrainian government, as well as the Saudi Crown Prince and the Foreign Office, for securing the release.

He added: "Aiden's return brings to an end months of agonising uncertainty for Aiden's loving family in Newark, who suffered every day of Aiden's sham trial but never lost hope.

"As they are united as a family once more, they can finally be at peace." 

Aiden Aslin arriving in Saudi Arabia after being released from captivity in Russia - AFP via Getty Images© Provided by The Telegraph

James Cleverly, the Foreign Secretary, said the release "brings to an end many months of uncertainty and suffering, including the threat of the death penalty, for them and their families, at the hands of Russia".

"Tragically that was not the case for one of those detained and our thoughts remain with the family of Paul Urey,” he added.

The British aid volunteer died earlier this year while being detained by Russian-backed separatists in Ukraine.

Mr Cleverly added: "I would like to express my gratitude to President Zelensky and his team for their efforts to secure their release, and to HRH Crown Prince of Saudi Arabia, Mohammed bin Salman and his team, for their assistance. 

"I continue to call on Russia to comply with international humanitarian law and not exploit prisoners of war and civilian detainees for political purposes."

In July, a court in the self-proclaimed Donetsk People's Republic had sentenced Mr Aslin to death alongside fellow British detainee Mr Pinner.

The Prime Minister, who is visiting New York for a United Nations summit where world leaders are discussing Russia’s invasion of Ukraine, tweeted:  

Ms Truss also said:  

She added: "Russia must end the ruthless exploitation of prisoners of war and civilian detainees for political ends.” 

Mr Harding, along with Mr Hill and Mr Healy, went on trial last month in the city of Donetsk, according to Russian media. 

The three, along with Swede Matthias Gustafsson and Croat Vjekoslav Prebeg, all pleaded not guilty to charges of mercenarism and "undergoing training to seize power by force".

The next court hearing in their case was scheduled for October, the Interfax news agency reported, citing a statement by the separatists' court.

Reports suggested the 10 prisoners included citizens of Sweden, Croatia and Morocco, as well as two US military veterans, Alex Drueke, 40, and Andy Huynh, 27.

Mr Byrne added that he was "completely relieved and so pleased" that the five had returned to Britain, but added that he was "still thinking" of Paul Urey's family.

Allan Hogarth, from Amnesty International UK, called it a "huge relief" after a "sham judicial process apparently designed to exert diplomatic pressure on the UK".