The Egyptian government denied a request for a public funeral from the family of former President Mohamed Morsi on Tuesday, quickly interring Morsi’s remains in the Nasr City district of Cairo.

Morsi collapsed in court on Monday and died in the hospital soon afterward. His family, and the international Muslim Brotherhood organization he belonged to, have accused the Egyptian government of causing his death with harsh prison conditions. Morsi reportedly suffered from a number of ailments, including diabetes and kidney disease. The preliminary ruling on his death said he suffered a heart attack.

The deposed president was serving a 20-year prison sentence for his role in killing protesters during his year in power, plus additional sentences for espionage and participating in a prison break during the fall of his predecessor, Hosni Mubarak.

According to lawyers and members of the family, Morsi’s family attended funeral prayers Tuesday morning at the mosque in the prison where he was incarcerated, then buried him at a cemetery where other senior Muslim Brotherhood figures are interred. The authorities refused the family’s request for a public funeral in their home province of Sharqiya, citing security concerns.

“We washed his noble body at Tora prison hospital, performed prayers for him in the prison mosque … The burial was at the cemetery for Muslim Brotherhood spiritual guides,” Morsi’s son Ahmed wrote on Facebook.

“Security agents turned reporters away from the cemetery, banning them from taking photographs of the funeral. Reporters were also barred from traveling to Morsi’s hometown,” NBC News reported.

The Muslim Brotherhood, which previously accused the Egyptian government of “assassinating” Morsi by allowing his health to deteriorate in prison, called his death a “full-fledged murder” and called on supporters to stage a mass funeral in addition to demonstrating at Egyptian embassies worldwide.

Following Morsi’s removal, Egypt joined the United Arab Emirates (UAE), Saudi Arabia, and Russia in branding the Muslim Brotherhood a terrorist organization.

Some observers criticized Morsi’s burial for its unseemly haste, which did not allow enough time for all of his family members to gather, and the refusal to allow him to be interred in his hometown in accordance with Egyptian burial traditions.

Two major international human rights organizations quickly called for a thorough investigation of Morsi’s death.

“The Egyptian authorities have an appalling track record of detaining prisoners in prolonged solitary confinement and in dire conditions as well as subjecting prisoners to torture and other ill-treatment. This makes it all the more crucial for the authorities to carry out an investigation to determine whether any such ill-treatment was a contributing factor to Mohamed Morsi’s death, and ensuring that those responsible for the violation of his rights are held accountable,” Amnesty International said on Monday.

“The Egyptian government deliberately singled out former President Morsi for especially harsh treatment and isolation. Whatever one’s views of Morsi’s politics, his treatment was horrific and those responsible should be investigated and appropriately prosecuted,” said Human Rights Watch.