Militants belonging to the Islamic State had reportedly demanded the release of Dr Aafia Siddiqui and others extradited to the United States in exchange for American photojournalist James Foley and other Western hostages, said a report published on The Independent.

An e-mail was sent to the family of Mr Foley in which the Al Qaeda splinter group had claimed that they had offered “prisoner exchanges to free the Muslims currently in your detention” which included Dr Aafia.

Dr Aafia, a Pakistani neuroscientist, was sentenced to 86 years in prison in 2010 by a US federal court for trying to kill US agents and military officers.

The e-mail said that despite offering prisoner exchanges to free those who were detained in the US, the government “proved very quickly that this is not what you are interested in”.

The report quoted the GlobalPost as saying that Foley’s family had received their first message from his captors last year on November 26, asking for money after more than a year had elapsed without any contact.

"After the militants had proved to the Foleys and investigators that they were in fact holding Jim, they made their sole demand for a ransom of 100 million euros (about $132 million) or the release of unspecified prisoners held by the United States," the GlobalPost said.

Some footage released by IS, which showed Mr Foley’s killing, also showed militants believed to be British threatening the life of another journalist Steven Sotloff.

The militant, who killed Mr Foley, spoke with a British accent and addressed US President Barack Obama, saying: “The life of this American citizen, Obama, depends on your next decision.”

The video claimed that Foley was killed in revenge for the ongoing US air strikes in Iraq.

Know more: Islamic State 'beyond anything we've seen': US