A second man from west London has been named as a member of the Isis execution squad spearheaded by so-called “Jihadi John”.

The group, known among their captives as “The Beatles” because of their British accents, were led by Londoner Mohammed Emwazi and have been described as some of the most brutal jailors in Isis’s ranks.

A second man in the terror cell can now be named as Emwazi’s friend Alexanda Kotey, according to an investigation by Buzzfeed News and the Washington Post, which first named Emwazi as “Jihadi John”.

Kotey, a 32-year-old convert who attended the Al-Manaar mosque in Ladbroke Grove, west London, alongside Emwazi, has separately been named by ITV News. The mosque has condemned their actions. The UK Foreign Office has declined to comment on the latest developments.

But according to the Post, Kotey’s identity has been confirmed by a US official and “other people familiar with British nationals in Syria”.

It remains unclear whether Kotey was the jailor known as “Ringo” or “George” – significant because those were the names they have gone by in previous accounts of their atrocities from hostages who were released.

“George”, according to a memoir by Danish hostage Daniel Rye, was the most violent and dominant of the group of British-accented jailors. “Ringo” reportedly kicked Rye 25 times in the ribs as a “gift” on his 25th birthday.

Between them, the four members of the “Beatles” cell tortured dozens of hostages and beheaded 27, including seven British, American and Japanese hostages and 18 members of the Syrian army.

A third man who also attended mosque with Kotey and Emwazi, Aine Davis, has previously been named as another suspect member of the Isis cell.

Davis was detained along with a group of other alleged Isis militants by Turkish police in Istanbul at the end of last year, and intelligence services said the group may have been planning an attack similar to the Paris shooting elsewhere in Europe.

According to Buzzfeed News, Kotey is half-Ghanaian, half-Greek Cypriot and grew up in Shepherd’s Bush as a fan of Queens Park Rangers.

He reportedly converted to Islam in his early twenties, and left two young children in Britain when he travelled to Gaza in 2009 as part of a controversial aid convoy organised by George Galloway.