The brother of a British aid worker killed by a so-called Islamic State terror cell known as “the Beatles” has welcomed the conviction of one of their members, saying: “An eight-year chapter of pain for my family has finally come to an end.”

Mike Haines, whose brother David Haines was murdered by the barbaric group, said the conviction of 33-year-old Londoner El Shafee Elsheikh in a US court on Thursday “provided us with some closure”.

David was captured by militants in Syria in March 2013 while delivering aid to the war-torn country.

His murder the following year was used for propaganda by “the Beatles”, who were given the moniker because of their distinctive British accents.

Elsheikh and fellow Beatle Alexanda Kotey will be sentenced for their part in the gruesome plot later this month.

In a statement, Mike Haines said: “While nothing can truly compensate for the hole David’s murder left in our hearts, the verdict provides us with some closure and ensures that all three surviving members of the gang involved in my brother’s murder have now faced justice.”

The cell, also said to be made up of ringleader Mohammed Emwazi, known as Jihadi John, and Aine Davis, was thought to be responsible for the brutal killings of several Western and Japanese captives, including Britons Alan Henning and Mr Haines.

The latter two did not form part of the indictment against Elsheikh and Kotey, the latter having already admitted his role in the atrocities, because the court was focusing only on US victims.

It is believed the pair may yet face court in the UK for the deaths of British nationals.

Mr Haines, who runs education charity Global Acts Of Unity in honour of his 44-year-old brother, said he is due to fly to the US for the sentencing hearing.

He said: “My brother and the many other innocent lives taken by this terrorist organisation were never afforded justice.

“This unanimous judgment is a triumph for society over ills like terrorism and helps differentiate us from the hateful, divisive ideologies that fuel these individuals.

“It must also act as a warning to anyone else seduced by the false glamour of extremism.”

Bethany Haines, the daughter of David Haines, said the conclusion of the trial was “a lot more emotional” than she expected.

Speaking after his conviction, Ms Haines told BBC One: “It was a lot more emotional than I expected.

“I expected to be happy, excited, but it’s the realisation that he’s guilty, what he’s done to all the families, all the hostages.

“I’ve not slept a full night’s sleep probably since my dad was killed in 2014 so hopefully tonight I’ll get a full night’s sleep.”

On Thursday, Elsheikh was convicted of eight counts relating to four US hostages, James Foley, Steven Sotloff, Peter Kassig, and Kayla Mueller, after a trial at the US District Court in Alexandria, Virginia.

Following the verdict, Commander Richard Smith, head of the Met’s counter terrorism command, said the force had provided evidence to the US court.

He added: “This evidence has contributed to the overall prosecution case, and enabled our colleagues in the US to ensure this man has been brought to justice for some of the most evil and terrible crimes imaginable.

“It shows how we, along with our international partners, are absolutely determined to identify and bring those responsible for extremely serious terrorist offences to justice, even if those offences have been committed on foreign soil.”

Elsheikh, Kotey and Emwazi all knew each other in England before joining IS, the court was told.

Elsheikh was captured alongside Kotey in Syria in 2018 by the US-supported Syrian Democratic Forces while trying to escape to Turkey.

Last year, Kotey pleaded guilty to eight counts relating to his involvement, while Davis was jailed in Turkey and Emwazi was killed in a drone strike.