On 18 March, 29-year-old blogger Alireza Mirsayafi died while in Tehran’s notorious Evin prison for insulting the country's supreme leader, Ayatollah Ali Khamenei.
Mohammad Ali Dadkhah said that although there is not yet an official report about the death yesterday of Omid Mir Sayafi, “officials in the prison said that he committed suicide."
He demanded “an immediate inquiry and an autopsy into why he died."
Mr Dadkhah said another prisoner in Evin, a Dr Hessam Firouzi, “had warned officials in the jail of the state the young blogger was in".
“Dr Firouzi called me from the jail to say he had a slowed heartbeat and he had taken him to the infirmary, but that doctors there did not take this seriously and said he was faking it,” he said.
He added that Dr Firouzi reported that Mr Sayafi had also been very depressed.
The blogger was sentenced in February to 30 months in jail for insulting Khamenei and Ayatollah Ruhollah Khomeini.
Mr Sayafi was first arrested in April last year and released on bail after 41 days before being detained again this year.
Iran has launched a crackdown on bloggers and internet users deemed to be hostile to the Islamic regime.
Those arrested include Hoder Derashkhan, a Canadian-Iranian journalist and blogger detained in Iran last November. Mr Derashkhan's family is said to have had no news of him since his arrest.