The American journalist Roxana Saberi was jailed for espionage in Tehran after obtaining a confidential Iranian document about the American invasion of Iraq, it was claimed today.

Saleh Nikbakht, one of Ms Saberi's Iranian lawyers, revealed that a document Ms Saberi had obtained while working as a translator for a powerful clerical lobby had been used as evidence to convict her on charges of espionage.

Ms Saberi, 32, was released on Monday after an appeal court dismissed charges of spying and reduced her eight-year prison term to a two-year suspended sentence.