CAIRO (Reuters) - An Egyptian rights group that treats torture victims was prevented on Thursday from accessing its funds and told that its account had been blocked, its lawyer told Reuters.

Taher Abu al-Nasr, who represents the Nadeem Center for the Rehabilitation of Victims of Violence and Torture, said an employee was not allowed to cash a check for the center and was told by a bank manager that the central bank had ordered its account suspended until it registers as a non-governmental organization with the social solidarity ministry.

Nadeem says it is registered as a clinic with the health ministry and does not need to register as an NGO.

“We couldn’t cash a check today. We don’t know exactly what happened; whether our assets are frozen or our account is shut down or what. We will try to obtain the written order on Sunday when banks reopen,” Abu al-Nasr said.

Egyptian authorities deny allegations by human rights groups and activists that security forces round up people and torture them in secret detention centres.

Amnesty International condemned the move against Nadeem, saying the NGO provides hundreds of torture victims with vital services including counselling and legal assistance.

“This is yet more evidence of the Egyptian authorities’ chilling contempt of perceived critics. By freezing Nadeem’s financial assets the authorities are preventing the Center from carrying out their crucial work to provide care to survivors of horrific violence,” said Philip Luther, Research and Advocacy Director at Amnesty for the Middle East and North Africa.

The government had already ordered the closure of the center in February without providing an official reason. Health ministry sources at the time said it committed unspecified violations.

The center challenged the order in court and still operates.

Egyptian rights activists say they are facing the worst assault in their history amid a wider campaign to erase freedoms won in a 2011 uprising that ended Hosni Mubarak’s 30-year rule as president.

In October, an Egyptian court approved a freeze on the assets of five prominent human rights activists and three NGOs accused of receiving foreign funds to sow chaos.

The groups accuse President Abdel Fattah al-Sisi’s government of widespread abuses, allegations it denies. As military chief, Sisi toppled Islamist President Mohamed Mursi in 2013 after mass protests against his rule.

Security forces killed hundreds of Mursi supporters in the streets and arrested thousands. Secular activists were later rounded up.