Iranian authorities have confirmed that an Iranian-Canadian environmentalist died in prison and said his death was a suicide, a claim his son said he does not believe.

Kavous Seyed-Emami “was one of the defendants in a spying case and unfortunately he committed suicide in prison since he knew that many had made confessions against him and because of his own confessions," Tehran's prosecutor Abbas Jafari-Dolatabadi told the semiofficial ILNA news agency on February 11.

Activists say there have been other suspicious deaths among detainees in Iranian prisons that authorities have labeled as suicide.

Seyed-Emami, 63, was arrested on January 24.

The Iranian authorities told Seyed-Emami’s wife that he had died in Tehran’s Evin Prison on February 9, his son said in social-media posts.

"The news of my father's passing is impossible to fathom,” Raam Emami wrote on February 10. “They said he committed suicide. I still can't believe this."

The family has asked for an independent autopsy, he wrote from an unknown location.

The Iran Sociology Association also questioned the official account of Seyed-Emami’s death.

In a statement issued on February 11, it said: "The information published about him is not believable and we expect officials to respond.”

Seyed-Emami, a U.S.-trained scholar, had been managing director of the Persian Wildlife Heritage Foundation, which seeks to protect Iran's rare animals.

He had taught sociology for decades at Tehran’s Imam Sadegh University, considered a hard-line institution where future leaders of the Iranian establishment are trained. Seyed-Emami had said he felt it was his duty to teach his opposing views.

A Canadian Foreign Ministry spokesman said authorities were looking into the matter.

The news of Seyed-Emami’s death comes as Iranian prison officials said two detainees arrested during the recent nationwide antigovernment protests had also committed suicide.

The detainees’ families and many activists, however, have disputed those conclusions and called for an independent probe.

With reporting by AFP, AP, The New York Times, Reuters, and BBC