london britain prepare transfer 400 million pound 527 million iran seek release jail iranian-british aid worker telegraph newspaper report cite unidentified british source nazanin zaghari-ratcliffe project manager thomson reuters foundation sentence five years convict iranian court plot overthrow clerical establishment deny charge britain seek legal advice whether could transfer fund owe result dispute arm deal 1970s diplomats tell newspaper payment link fate zaghari-ratcliffe thomson reuters foundation charity organization independent thomson reuters operate independently reuters news spokesman britain foreign office could reach comment normal business hours britain prepare transfer 400 million pound iran telegraph newspaper