Son of leading scientist dies in jail.

Supporters of defeated Iranian presidential candidate Mir Hossein Mousavi run in the streets during protests in Tehran, Iran, June 16, 2009. Photograph: Getty Images/Getty Images

Fears are mounting over the safety of hundreds of political inmates in Iran's most notorious prison following the deaths of two prisoners detained in the recent post-election unrest.

Mohsen Rouholamini and Amir Javadifar died in Tehran's Evin prison after being arrested at a demonstration this month. Rouholamini, the son of a prominent Iranian scientist close to the country's political elite, died from meningitis after injuries believed to have been inflicted by his jailers went untreated.

The deaths prompted fears of a meningitis outbreak in Evin and other overcrowded detention centres where opposition figures, journalists and students are kept following last month's disputed election. News of the deaths coincided with reports of injuries to other detainees.

One inmate, Isa Saharkhiz, a prominent reformist journalist and commentator, is reported to have suffered broken ribs after being tortured under interrogation.

Campaigners are also concerned for the safety of Kian Tajbakhsh, an American-Iranian scholar said to be under pressure to confess involvement in an alleged western plot to orchestrate the protests following Mahmoud Ahmadinejad's re-election.