An Irish citizen held in Iran has suspended his dry hunger strike at the request of his family, who fear for his life, his sister said.

Bernard Phelan, detained in Iran since early October, will accept food and fluids again, Caroline Masse-Phelan said, but remains "determined", and will "start again if there is no progress".

Mr Phelan, a Paris-based travel consultant and one of seven French nationals held by Iran, was arrested while travelling and is being held in Mashhad in northeastern Iran.

Iran accuses him of anti-government propaganda, a charge he has denied.

He started refusing food on 1 January and fluids on Monday. Mr Phelan, who suffers from a heart condition and a chronic bone issue, was judged to be in critical condition by Wednesday.

Ms Masse-Phelan said earlier in the week the family had managed to pass messages to her brother through diplomatic channels.

"Bernard has agreed to read our messages and has suspended his hunger and thirst strike," she said today.

"His life is still in danger," she said, adding that her brother had received no medical attention, and was "not well", suffering from "an enormous drop in blood pressure".

The Iranian authorities have so far refused to release Mr Phelan on medical grounds despite repeated requests from the French and Irish authorities, a French diplomatic source said.

Mr Phelan, who also holds French citizenship, is one of two dozen foreigners who are being held in Iran, according to activists, who describe the detainees as "hostages" seized to extract concessions from the West.

Mr Phelan was travelling through Mashhad during the ongoing protests against Iran's clerical regime when he was arrested.

Fellow French national Benjamin Briere, who was sentenced last year to eight years in prison on spying charges, is being held in the same prison.

"We are extremely worried for Bernard Phelan," a French foreign ministry official said today.

"We hold Iran entirely responsible for his situation, and for the state of his health," said the source, who declined to be named.

Diplomats said earlier that Mr Phelan received his first French consular visit only on 9 January, after repeated requests.