Human rights groups are calling for the release of a Saudi woman, who they say has been sentenced to 11 years in prison for supporting women’s rights and for the way she dressed.

Manahel al-Otaibi, a 29-year-old fitness instructor and women’s rights activist, was sentenced during a “secret hearing” before the kingdom’s Specialized Criminal Court on January 9, 2024, Amnesty International and the London-based Saudi rights organization ALQST said in a joint statement Tuesday.

However, the decision to imprison al-Otaibi only surfaced weeks later, after the Saudi government replied to a request by United Nations Special Rapporteurs for information about the case, the watchdogs say.

Al-Otaibi “stands accused of terrorist offences and was arrested in accordance with the law under a legally valid warrant,” Saudi Arabia’s mission to Geneva said in a letter in January, in response to the UN request.

Amnesty and ALQST allege Al-Otaibi’s charges are related “solely to her choice of clothing and expression of her views online, including calling on social media for an end to Saudi Arabia’s male guardianship system, publishing videos of herself wearing ‘indecent clothes,’ and ‘going to the shops without wearing an abaya’.”

Her sister, Fawzia al-Otaibi, faces similar charges but was able to flee Saudi Arabia after she was summoned for questioning in 2022, they said.

Saudi Arabia’s authorities “must immediately and unconditionally” release Manahel al-Otaibi, as the decision to imprison her “directly contradicts the authorities’ narrative of reform and women’s empowerment,” Amnesty and ALQST said.

“Manahel’s conviction and 11-year sentence is an appalling and cruel injustice,” said Bissan Fakih, Amnesty International’s Campaigner on Saudi Arabia. “With this sentence the Saudi authorities have exposed the hollowness of their much-touted women’s rights reforms in recent years and demonstrated their chilling commitment to silencing peaceful dissent.”

Following her arrest, al-Otaibi was subjected “to physical and psychological abuse” in the Malaz Prison in Riyadh, the groups said. She told her family in April that she was being held in solitary confinement and had a broken leg as a result of physical abuse, Amnesty and ALQST said. CNN is unable to independently verify these claims.

CNN has reached out to the Saudi government for comment on the accusations.

In its letter to the Office of the UN High Commissioner for Human Rights, the kingdom’s mission to Geneva said that “no person is held in detention in Saudi Arabia for exercising their rights and freedoms,” and that “state institutions have a legal obligation to ensure that all individuals are treated fairly irrespective of their religion, race, sex or nationality.”

While Saudi authorities have removed some of the restrictions on women under the male guardianship system, “many discriminatory features remain in place,” the watchdogs said.

“The long-awaited 2022 Personal Status Law, which was supposed to be a major reform, in fact serves to codify rather than abolish many restrictive elements of the system, including matters of marriage, divorce, child custody and inheritance,” Amnesty and ALQST said.

Al-Otaibi “ironically” believed in Crown Prince Mohammed bin Salman’s pledge for reforms, “yet she was arrested on 16 November 2022 for exercising exactly these freedoms,” Amnesty and ALQST said.

Al-Otaibi’s sentencing comes “amid an intensified crackdown on free speech in Saudi Arabia, including online expression,” the groups said. Over the last two years, Saudi courts have “handed down lengthy prison terms on dozens of individuals for their expression on social media, including many women,” they said.