Reza Saberi said he and his wife Akiko visited their daughter Roxana in Teheran's Evin jail on Sunday, taking flowers for her 32nd birthday.

The 68-year-old said he had asked his daughter to stop her action, but she did not want to discuss it during the 20-minute visit. She started refusing food last Tuesday, he said.

The freelance reporter was sentenced to eight years in jail on April 18, in a verdict that could complicate Washington's efforts towards reconciliation with Iran after three decades of mutual mistrust.

A citizen of both the United States and Iran, Ms Saberi was arrested in late January for working in the Islamic Republic after her press credentials had expired. She was later charged with espionage.

US President Barack Obama has expressed deep concern for Ms Saberi's safety and Secretary of State Hillary Clinton has said releasing her would serve as a goodwill gesture. Teheran, which does not recognise dual nationality, says Washington should respect the independence of Iran's judiciary.

Ms Saberi's defence lawyer, Abdolsamad Khorramshahi, said on Saturday he had appealed against the eight-year jail sentence.

Iran's Nobel Peace Prize winner Shirin Ebadi had agreed to help defend Ms Saberi but prison officials refused to let a member of the reporter's team see their client, said Mr Ebadi's aide.

Reporters Without Borders, the Paris-based media rights group, has called Ms Saberi's conviction 'unjust under the Iranian criminal code", saying it was a warning to foreign reporters working in Iran before its presidential election in June.

Amnesty International said she was a 'pawn to the ongoing political developments' between Iran and the United States. -- REUTERS