Amnesty International said the continuing crackdown laid bare the hollowness of Iran’s claims to support protests in the Middle East and North Africa.
“In Iran today you put yourself at risk if you do anything that might fall outside the increasingly narrow confines of what the authorities deem socially or politically acceptable,” said Ann Harrison, Interim Deputy Director of Amnesty International’s Middle East and North Africa Programme.
“Anything from setting up a social group on the internet, forming or joining an NGO, or expressing your opposition to the status quo can land you in prison.”
“This dreadful record really highlights the hypocrisy of the Iranian government's attempts to show solidarity with protesters in Egypt, Bahrain and other countries in the region.”
The report finds that in recent months a wave of arrests has targeted a range of groups, including lawyers, students, journalists, political activists and their relatives, religious and ethnic minorities, filmmakers, and people with international connections, particularly to media.
Opposition leaders Mir Hossein Mousavi and Mehdi Karroubi – defeated presidential candidates in the 2009 election – have been under de facto house arrest since February 2011. While Mehdi Karroubi’s wife was released in July 2011, Zahra Rahnavard, Mir Hossein Mousavi’s wife, remains under house arrest with her husband.
In the run-up to parliamentary elections on 2 March, the situation has worsened.
The clampdown has targeted electronic media, seen by the authorities as a major threat. In January a senior police officer said Google was an “espionage tool”, not a search engine. The same month, the recently established Cyber Police required owners of internet cafés to install CCTV and to register the identity of users before allowing them to use computers.
Blogger Mehdi Khazali was this month sentenced to four and a half years in prison, followed by 10 years in “internal exile”, and a fine on charges believed to include “spreading propaganda against the system” “gathering and colluding against national security,” and “insulting officials.” It is not clear whether his “internal exile” will in fact be served in prison.
Having been originally charged in 2011 and released on bail, he was arrested again in January. He is being held in Tehran’s Evin Prison, where he has been on hunger strike for more than 40 days in protest at his detention, raising fears for his health.
Harassment, arrest and imprisonment of human rights defenders, including women’s rights groups, has also intensified and several NGOs have been shut down.
Abdolfattah Soltani, a founder member of the Centre for Human Rights Defenders, was arrested in September and is held in Evin Prison awaiting the outcome of his trial on charges which include his acceptance of an international human rights prize. He has been threatened with a 20-year sentence.
The pressure on independent voices has extended to those outside Iran.
Earlier this month, the BBC said family members of its Persian language service had been subjected to harassment, including one who was arrested in January and held in solitary confinement and others whose passports were confiscated.
Amnesty International said the attacks on dissenting views come against a backdrop of a worsening overall human rights situation in Iran.
There were around four times as many public executions in 2011 as in 2010, a practice that Amnesty International said was used by the authorities to strike fear into society.
Hundreds of people are believed to have been sentenced to death in the past year, mainly for alleged drugs offences. Iran continues to execute juvenile offenders – a practice strictly prohibited under international law.
Amnesty International called on the international community not to allow tensions over Iran’s nuclear programme or events in the wider region to distract it from pressing Iran to live up to its human rights obligations.
The organization specifically urged the UN Human Rights Council to renew the mandate of the Special Rapporteur on Iran in March.
"For Iranians facing this level of repression, it can be dispiriting that discussions about their country in diplomatic circles can seem to focus mainly on the nuclear programme at the expense of human rights," said Ann Harrison.
"Countries dealing with the Iranian government cannot neglect their responsibilities to Iran's brave rights defenders, trade unionists, minorities and journalists."