An Iranian environmentalist who was held by the intelligence branch of Iran's Islamic Revolutionary Guards Corps (IRGC) said she was interrogated and tortured for more than 1,200 hours, according to a BBC Persian report.

Niloufar Bayani, who is serving a 10-year prison sentence, said Iranian authorities threatened her with death and rape, while also forcing her to make animal noises.

The measures were aimed at breaking her down until she confessed to charges brought against her, including "cooperating with the hostile state of the US”.

Bayani was among eight members of the Persian Wildlife Heritage Foundation who were detained in Iran in 2018 on charges of spying - an allegation routinely thrown around by Iranian authorities to hold Western visitors, including journalists and academics.

The team were detained after taking pictures and tracking several endangered species in a "strategic area”.

The director of the Persian Wildlife Heritage Foundation, Kavous Seyed Emami, who was arrested alongside BAyani in 2018, died in detention just days later. The cause of death remains unknown, though authorities claim he had committed suicide.

Documents released by BBC Persian detailed how interrogators had forces Bayani to perform sexual acts.

"They would…[force] me to complete their sexual fantasies," Bayani had said in documents seen and verified by the BBC.

"I was increasingly terrified that if I didn't write whatever [my interrogator] wanted, he would sexually assault me," Bayani wrote.

The team had allegedly travelled back to Iran in a bid to help the country, but authorities were quick to accuse them of spying. Since the group's arrest, several senior Iranian officials have voiced the fact there has been no evidence to indicate the detained activists are spies.

In February 2019, Tehran MP Mahmoud Sadeghi even tweeted he had received information that the National Security Council, headed by President Hassan Rouhani, did not deem the environmentalists' activity to be spying.

In an earlier trial, Bayani said "If you were being threatened with a needle of hallucinogenic drugs [hovering] above your arm, you would also confess to whatever they wanted you to confess," according to Human Rights Watch (HRW).

The global rights group has slammed Iranian authorities for detaining the team, noting the Islamic Republic has yet to provide evidence against them.

"Iran's revolutionary courts are 'revolutionary' only in their ability to fabricate charges without evidence," Michael Page, deputy Middle East director at HRW, said in a February 19 statement.

"Two years on, there's still not a shred of evidence against these environmental experts, and the authorities should release them immediately," he said.

HRW called for the immediate release of all members of the group, whose trial has been riddled with accusations of psychological torture that coerced them into giving confessions. The defendants have also not been allowed to choose their own lawyer, instead forced to be represented by lawyers pre-approved by the judiciary.

The group has already spent two years behind bars since their arrests in early 2018. Four of the activists were initially charged with "sowing corruption on earth", which carries the death penalty. They were cleared of the charge in October 2019.

Iran is holding numerous Western citizens in prison, adding to tensions between Tehran and the West following the unilateral rejection by the US of the 2015 deal on the Iranian nuclear programme.

According to rights groups outside Iran, at least 11 foreign or dual nationals are currently being held in Iranian prisons following arrest by the Revolutionary Guards or intelligence ministry.

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