Ali Tavakoli told RFE/RL's Radio Farda that his brother was allowed to call home on May 29 and inform his family about his transfer from solitary confinement to the general ward.
Majid Tavakoli began a hunger strike about a week ago after being transferred to solitary confinement.
Ali Tavakoli credited support from Iranians all over the world as the reason for his brother's transfer to the general ward.
Many Iranians inside and outside the country had called Tavakoli’s family to express their support and solidarity. Opposition websites reported that opposition leaders Mir Hossein Musavi and Mehdi Karrubi also called on Tavakoli’s family and expressed their concern over his fate.
Two more prisoners jailed in the postelection crackdown -- right activist Kouhyard Goudarzi and blogger Hossein Rounaghi -- are said to have also gone on hunger strike to protest their conditions.
In recent years, hunger strikes have become one of the only means of protest for political prisoners in the Islamic republic.
-- Golnaz Esfandiari