Karami was hanged on January 7, just 65 days after his arrest.

He was one of the four men executed for their involvement in nationwide protests in Iran four months ago related to the death of Mahsa Amini, who died in police custody after being arrested for "improperly" wearing her hijab.

Another 18 have been sentenced to death, but not yet executed.

A source close to BBC Persian said Karami was given less than 15 minutes to defend himself in his trial.

Following Amini's death, protests erupted in the country, demanding improved rights for women.

The hijab, a type of headscarf, is compulsory for women in Iran.

The Iranian Government called the protests rioting, cracking down on activism which led to the deaths of 481 people, according to non-governmental organisation Iran Human Rights.

Karami was arrested in connection with the murder of a paramilitary force member in Karaj on November 3 and was later charged with a capital offence.

On November 30, he went on trial with 16 others, including three children.

On December 5, he was sentenced to death with four co-defendants, while 11 others were given lengthy prison terms, including the minors.

Tasvir, an opposition activist group, claim prior to his death, Karami was beaten unconscious by guards and threatened with rape.

Other inmates, including Seyed Mohammad Hosseini who stood on trial alongside him, recall similar torture before he was hanged the same day as the karateka.

Iran Human Rights reports at least 109 protestors are at risk of execution.