Prominent Iranian-Canadian environmentalist Kavous Seyed-Emami died in custody in Tehran a fortnight after his arrest, activists and a family member said on Sunday.
A judiciary official claimed on Sunday that he had confessed to crimes related to an espionage investigation, and seven other members of his wildlife NGO are still behind bars.
Asked about Emami's case, judiciary spokesman Gholamhossein Mohseni Ejeie told the reformist ILNA news agency: "I have heard he committed suicide but I have so far no information on the details".
The arrests were not publicly disclosed until Seyed Emami's family on Saturday announced his death. "This is a prison system out of control and a Judiciary that is actively colluding in a massive cover-up", said Hadi Ghaemi, executive director of CHRI.
The acquaintance said the case is likely to have a chilling effect on dissent in the country, where more than 90 cities and towns were hit by social protests in December and January, leading to dozens of deaths and thousands of arrests.
"The news and rumors related to his arrest and death are not believable", Iran's Society of Political Science, Iran's Society of Sociology, the Society of Peace Studies, and the Association for Cultural Studies and Communications said in a joint statement.
"I still can't believe this", he wrote.
Among them was Hooman Jokar, who headed a program to save the endangered Asiatic cheetah.
The most recent arrests also suggested that environmental issues - a spark for the recent protests - were becoming increasingly politically sensitive in Iran. Local officials said he had stabbed himself to death.
A senior official at the EPO, who did not wish to be named, told AFP on Monday that this was incorrect and that Madani was at work.
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Three decades later, Jordan Greenway is part of the 0.008 percent of current college players who identify as African American. The City of Toronto has passed legislation allowing licensed bars and restaurants to start serving alcohol at 7 a.m.
"Tehran's prosecutor said those individuals, in the context of implementing scientific and environmental projects, sought to collect information. on the country's strategic areas", a report by the state-run IRNA news agency said, without elaborating.
"He was one of the best professors", the academic said.
Meanwhile, the deputy head of Iran's Environmental Protection Organisation, Kaveh Madani, appointed by President Hassan Rouhani a year ago, released a video that appeared to support claims that he too had been temporarily detained in recent days.
"Canadian consular officials in Ankara are working to gather additional information and are providing assistance to the family of the Canadian citizen", said the spokeswoman, Natasha Nystrom.
Now that Iranian-Canadian Kavous Seyed Emami has died suspiciously in custody, the family has the right to order an autopsy.
Others with ties to the West detained in Iran include Chinese-American graduate student Xiyue Wang, who was sentenced to 10 years in prison for allegedly "infiltrating" the country while doing doctoral research on Iran's Qajar dynasty. "On his return, he was called in several times" by the authorities.
Emami is the second Iranian-Canadian citizen to die in Iran's prisons following the murder of 54-year-old Zahra Kazemi in 2003, who had been arrested for taking photos outside Evin Prison.
The vice-president at the time, Mohammad Ali Abtahi, stated she died from "a brain hemorrhage caused by a beating".
Canada's Ankara embassy deals with Iranian affairs since the country severed diplomatic relations with Iran in 2012 over its support for the Syrian regime, "incitement to genocide" against Israel and its leaders' failure to account for their nuclear programme.
Although Mr. Alghabra said the investigation should address the cause and circumstances surrounding Mr. Seyed-Emami's death, it's not clear if Canada specifically asked for an autopsy.