The Islamic State militants who beheaded American journalist James Foley had demanded a ransom of £80 million ($132 million) for his release, a US official says.
The demands were sent in emails to Mr Foley's family in New Hampshire.
Mr Foley's former employer, publication GlobalPost, said that the militants first demanded the money late last year.
US policy prohibits the government negotiating with terrorists, including paying ransom.
A British family have told ITV News of their devastation after discovering a close relative is fighting with the Islamic State in Iraq.
A French journalist who was held hostage with James Foley in Syria has told ITV News it was "devastating" to see his murder.