Aine Davis, from Hammersmith, West London, could be deported back to the UK within weeks, as he approaches the end of a prison sentence in Turkey.
He was convicted of membership of ISIS in 2017 and sentenced to seven-and-a-half years in prison, following his arrest by Turkish security forces two years earlier.
Davis is currently being held at Sincan maximum security prison in the Turkish capital Ankara.
According to Turkish official sources, quoted by the online news site Middle East Eye, he is scheduled to be released and deported to the UK on July 9.
However, the publication also reported that procedures, such as a mandatory comprehensive health check and his appearance in front of a probation board, could delay his release by a few months.
Davis was arrested by Turkish counter-terrorism police in a raid on a villa in Silivri, a western suburb of Istanbul, on November 12 2015.
Mohammed Emwazi, or Jihadi John, was a fellow Beatle with Davis
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Turkish prosecutors accused him of being a “known high-ranking operative of Daesh [ISIS]”, and said he had been tracked as he crossed the border from ISIS-controlled Syria and made his way across Turkey.
The Home Office has declined to comment on whether Davis retains his British citizenship.
It is thought he may have dual Gambian nationality through his father. He also lived there between the ages of five and 17.
Under UK immigration law, British citizenship can be "deprived" if the Home Secretary is satisfied that the deprivation is "conducive to the public good" because the person has conducted themselves in a manner which is "seriously prejudicial to the vital interests of the United Kingdom or associated territories".
The Secretary of State must have “reasonable grounds for believing that the person is able, under the law of a country or territory outside the United Kingdom, to become a national of such country or territory".
Aine Davis
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Priti Patel can 'deprive' British citizenship
Danny Lawson
If he is deported back to the UK, plans are in place to deal with the security implications of his return.
GB News has been told he could be arrested on landing back in the country.
Although he has already been convicted and jailed for his membership of a proscribed group, he could still face charges in a British court, such as “Preparing Acts of Terrorism”.
Even if not charged with a specific criminal offence, he would face significant restrictions, and would likely be the subject a Terrorist Prevention Order (TPIM).
The "Beatles" were responsible for the kidnap and imprisonment of more than 20 Westerners, and the execution of at least seven of them, including Britons David Haines and Alan Henning.
Survivors of the kidnap gang told of how they nicknamed their captors "the Beatles" because of their British accents.
The group included Mohammed Emwazi from Queen's Park, West London – who became known as “Jihadi John."
He was killed in a drone strike in the Syrian city of Raqqa in 2015.
El Shafee Elsheikh and Alexanda Kotey, also from West London, were two other members of the gang.
They were captured by the Western-backed Syrian Democratic Forces in 2018 and extradited to the US to stand trial.
Davis was only referred to in the indictment of the two men, as "co-conspirator 1, a British citizen who is currently incarcerated in Turkey on a terrorism-related offence".
He did not feature in El Sheikh's trial and Kotey's plea agreement said only that he left Britain on February 17 2012 on the Eurostar, through the Channel Tunnel, with "co-conspirator 1" and two other friends who later died in the fighting in Syria.
However, he was mentioned extensively in the trial of his wife, Amal el-Wahabi, at the Old Bailey in July 2014, when the court heard Davis had “fulfilled his desire and was now with jihadist fighters and supporting the familiar black flag adopted by extremist jihadist terrorist groups in various countries in that troubled part of the world".
Prosecutors claimed “the overwhelming inference to be drawn from the available evidence is that he was taking part in violent conflict which has engulfed large parts of Syria".
That could leave Davis open to a prosecution for preparing acts of terrorism abroad, which can carry a life sentence, but has seen maximum sentences of around 12 years.
At his trial in Turkey, Davis denied being a member of ISIS and denied being a member of “the Beatles” kidnap gang.
He said he believed he had been linked to Mohammed Emwazi because the men had attended the same mosque in London.
Kotey, 38, from Shepherd's Bush, West London, was jailed for life, in Virginia, in April, after admitting kidnap, conspiracy to murder and providing material support for terrorism.
El Sheikh, 33, from White City, West London, was found guilty following a trial and will be sentenced later this year.
El Shafee Elsheikh was also a Beatle
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