An international human rights group said Sunday that an Iranian family only learned of the death of their 19-year-old son weeks after he was shot during a demonstration against the country's disputed presidential election.

The International Campaign for Human Rights in Iran said that it has raised concerns about the fate of what it said were dozens and possibly hundreds of other Iranians who disappeared in the postelection turbulence and remain unaccounted for.

According to the official death toll given by Iranian police, at least 20 protesters and seven members of the pro-government Basij militia were killed in the unrest that followed President Mahmoud Ahmadinejad's disputed June 12 re-election. It was unclear if the death revealed Sunday was counted among them.

• Click for more photos from Iran.

The New York-based human rights group said the protester, Sohrab Aarabi, was shot in the chest during a demonstration on June 15.

The young man's mother went daily to the Revolutionary Court and Evin prison in Tehran's northern suburbs to demand information about her son, the group said. But only on Saturday was she referred to the police's Investigation Bureau, where she identified her son among a series of photographs of the dead.

"The lack of transparency and calculated delay in releasing the information about Aarabi's unexplained death only raises anxieties about scores of others who are among the disappeared as well as those who have been held in incommunicado detention, with no contact to family members or lawyers, many for almost a month," the group said in a statement.

The rights group said its account of events was based on information from a phone conversation with Aarabi's aunt, who lives in Germany.

Iran has said that most of the more than 1,000 people it says were detained have been released, but arrests have continued.

Besides those rounded up in street demonstrations, more than 200 prominent Iranian lawyers, activists, journalists, professors and students remain unaccounted for after being detained at their homes by unidentified agents and taken to undisclosed locations, the rights group said.

"There are many disappeared persons who could now be languishing in secret prisons or could even be dead like this (Aarabi's) case," said the group's spokesman, Hadi Ghaemi.

Adding to the mystery surrounding Aarabi's killing, the group said his body was only delivered to the coroner's office four days after he was shot, raising questions about whether he died at the scene or was taken to a hospital while in authorities' custody.

Also Sunday, the Paris-based group Reporters Without Borders said that it knew of 41 journalists being held in Iran, some of them in secret locations.

"Iran is already the world's biggest prison for journalists and cyber-dissidents and is on the way to becoming the world's most dangerous place for them to operate," the press freedom group said.

Iran has restricted media during the election aftermath, barring journalists for international news organizations from reporting on the streets and ordering them to stay in their offices.