Two British extremists believed to have been members of Islamic State’s brutal executions group dubbed “The Beatles” have reportedly been captured.

Alexanda Kotey and El Shafee Elsheikh were detained by US-allied Kurdish militia fighters in January, according to US officials.

They were the last two members of a group of four from London to remain at large. They had been nicknamed “the Beatles” because of their English accents.

The four Londoners were linked to a string of hostage murders in Iraq and Syria during the bloody Islamist uprising.

Their alleged ringleader Mohammed Emwazi -- dubbed Jihadi John -- was killed in an air strike in Syria in 2015.

He had been responsible for the killing of Scottish aid worker David Haines who was beheaded by the terrorist group in September 2014.

Unnamed US Officials told the New York Times that Kotey and Elsheikh were captured by the Kurdish-led Syrian Democratic Forces which were fighting the last remaining pockets of IS fighters near the river Euphrates on the Iraq/Syria border.

The other suspected member of the cell was Aine Davis, who was jailed in Turkey last year on terrorism charges.

It added that the men were identified by fingerprints and other biometric means.

Former child refugee Elsheikh was a mechanic from White City in west London, and Alexanda Kotey was from Paddington.

In January 2017, US authorities named Kotey as a member of the cell and said they had imposed sanctions on him.

The fourth member, Davis, was convicted of being a member of a terrorist organisation and jailed for seven-and-a-half years at a court in Silivri, Turkey, in May 2017.