The sister of an Irish man being detained in a prison in Iran has said his physical health is declining rapidly and he is extremely fragile.
Bernard Phelan who is originally from Clonmel, Co Tipperary was arrested last October while travelling in Iran and is being detained in Mashhad.
The 64-year-old travel consultant who suffers from a heart condition and a chronic bone issue also holds French citizenship.
His family will hold a vigil outside the Iranian embassy in Dublin next Thursday.
Speaking to RTÉ's Saturday with Colm Ó Mongáin, his sister Caroline Masse Phelan said: "He has several health issues, cardiac and bone issues.
She said: "But also he is going blind because he had an operation last summer which was fine and went well but it hasn't been treated so he can't see very far anymore and he is very concerned that won't be repairable when he comes home."
She said in the prison where he is being held, medical care is very limited and the doctors want to increase his blood pressure medication "but he [Bernard] fears their competency" and as a result has refused the extra medication.
"He is afraid of what could happen to him there," Ms Masse said.
She said her brother fears for his safety and is extremely depressed due to the length of time he has been in jail and he doesn't see a way out.
She said he understands that the Government is in close contact with the Iranians but he doesn't see the fruits of that.
"He knows we are talking to the media, but again he doesn't see any fruit to that. He regularly tells us that he doesn't know how long he can hold on," she said.
Ms Masse said her brother needs to be released on humanitarian grounds.
She is appealing to people to sign a petition - which is available on releasebernardphelan.com - to call for the release of her brother. They are hoping to have 5,000 signatures before 30 March.
On that day Bernard's father will hand over the petition to the Iranian embassy in Dublin.
