Islamic State victim's mother 'begged' for daughter's release before her murder

The parents of a US aid worker kidnapped and killed by the Islamic State group (IS) in Syria begged for their daughter's release, a US federal court has heard.

Kayla Mueller's mother Marsha testified on Tuesday at the trial of El Shafee Elsheikh - also known as Jihadi George - who was an alleged member of a group of British IS fighters known as the IS 'Beatles'.

Elsheikh - who was stripped of his British citizenship in 2018 - has been accused of involvement in the murder of Mueller and three other Americans including journalist James Foley.

The Sudanese British-born 33-year-old - who has denied charges of hostage-taking and conspiracy to murder - is the highest profile IS fighter to face trial in the US.

Mueller told the court about email exchanges with her daughter's captors, who demanded a ransom of five million Euros or the release of Aafia Siddiqui, a Pakistani woman who is imprisoned in the United States for the attempted murder of US soldiers.

"We don't want to harm her," the hostage takers said in a May 2014 email, as they warned the Muellers that their daughter - would serve a "life sentence just like Siddiqui" if they could not meet their demands.

The Muellers told the kidnappers they were asking for "an astronomical amount of money from a family with limited resources" and explained that Kayla's father Carl was retired.

The parents received a reply stating "retiring will not help you get your daughter back so go back to work and earn some money".

Mueller's mother then appeared in a video message appealing to then-IS leader Abu Bakr al-Baghdadi saying "Kayla is not your enemy... show your mercy and release our daughter".

After failing to respond to subsequent emails sent by Mueller's family, IS claimed in February 2015 that Kayla had been killed in an airstrike by Jordanian warplanes in Syria's northeastern province of Raqqa.

Elsheikh - who has also been accused of appearing in execution videos and propaganda for IS - has been linked to at least 27 abductions between 2012 and 2015, but has asserted that he was not part of the IS Beatles, who were given their name due to the members' British accents.

The accused's lawyer claims Elsheikh's arrest is a case of mistaken identity.

Marsha Mueller's emotional testimony came on the fifth day of the trial in US federal court of El Shafee Elsheikh, which is expected to last three to four weeks. Elsheikh faces life in prison if convicted.