The siblings of a detained Iranian student have dismissed a judiciary claim that their brother has ties to the exiled opposition Mujahedin-e Khalq Organization (MKO or MKE).

Speaking on May 5, judiciary spokesman Gholam Hossein Esmaili accused two students detained last month of contacts with the MKO, which is considered a terrorist group by the Islamic republic.

The group, aka the People's Mujahedin Organization of Iran, which collaborated with Iraqi dictator Saddam Hussein during the 1980-88 war between Iran and Iraq, was removed from the U.S. list of terrorist organizations in 2012.

Esmaili said the two students, whom he did not name, had "explosives" in their homes, while adding that they had been trained to conduct terrorist operations in the country.

He appeared to be referring to two award-winning students from Tehran's top Sharif university, Ali Yunesi and Amir Hossein Moradi, who were arrested on April 10 on unknown charges. He did produce any of the evidence.

Yunesi's siblings, who are based outside of Iran, said the charges were "ridiculous," while accusing the judiciary of covering up the truth about the arrest of their brother.

Reza Yunesi told the BBC that the authorities appeared to be pressuring his family due to his parents' past MKO membership.

He said his parents, who still live in Iran, had not been members of the group for years.

He added that his brother was not politically active and that the family had not been able to hire a lawyer for his detained brother.

Yunesi's sister, Ayda Yunesi, said in a video posted on Twitter that security officers who raided her parents' home in the Iranian capital had said that they did not find anything suspicious.

She said the judiciary did not have any evidence against her brother.

"The best you could do is to link him to those opposing you and misuse the distant past of his parents to cover up the truth," she said, while suggesting that the authorities could pressure her brother to make a false confession.

A number of former detainees have said in recent years that they had been forced to confess to charges brought against them by their interrogators.

Moradi's family has not publicly commented on his arrest and the charges against him.