Mohammad Reza Pourshajari , a jailed blogger known by his pen name Siamak Mehr, wrote  an open letter from prison where he spoke of torture and extremely difficult conditions in prison. The letter, dated March 6, 2014 was widely republished by many websites at the end of March.
The 52-year old blogger is serving a 4-year sentence in Ghezel Hesar Prison in Karaj, which is north-west of Tehran. He was arrested on September 12, 2010 on charges of insulting the Prophet and enmity towards God in his blog  posts.
In the letter, Pourshajari wrote :
… as soon as I was arrested in my apartment by security forces, I was tortured, beaten and threatened to be executed… I am one of the victims of the Islamic regime's repression. I was sentenced to four years in prison for writing about injustice and violation of rights of [Iranian] citizens… I am writing this letter in a 21 square meter cell with 40 cellmates who are criminals, rapists, drug addicts… The Islamic Republic systematically represses fundamental civil rights and deprives people of freedom.
At the end of the letter, he invites the international community and governments who care for human rights to help Iranian people win their rights and freedom.
The authorities are refusing the transfer of Mr. Pourshajari to a medical facility and are depriving him of all his medications, in the hope that he will soon die. To [the prison authorities], the doctors’ opinions are of no importance; they completely ignore them…. All Iranians are forced to obey and do whatever pleases the system.
A Facebook page  has been launched to support the jailed blogger, with a copies of his letters and updates on his situation.
Here is a video, uploaded in December 2011, showing Siamak Mehr in chains, apparently on his way to court.