A man in his 90s is to hand over a petition to the Iranian embassy this week calling for the release of his seriously ill son.
Tipperary-born travel consultant Bernard Phelan, 64, has been held in a prison in the city of Mashad since last October.
Caroline Masse-Phelan, a sister of Mr Phelan, said her family intend to hold a vigil outside the embassy on Thursday amid growing concern about the fragile condition her brother.
