An Egyptian-American activist who was arrested after a protest in August detailed the horrors he encountered at a Cairo prison in a letter he managed to smuggle out.

Graduate of Ohio State University Mohamed Soltan was a media spokesperson for a protest camp in the capital city's Rabaa al-Adawiya Square. He participated in a rally that called for the return of ousted President Mohamed Morsi when he was shot in the arm by security troops who opened fire on the protestors.

Hundreds were killed after the demonstration, TIME reported.

Soltan said that he worried he'd be taken into government custody if he sought medical help from a public hospital, so he had the bullet extracted by a private doctor. Soltan was arrested days later, then taken to a prison in Cairo, where he said he encountered violent high-level personnel who beat him and the other prisoners.

"The brutality with which I have been treated has been mind boggling," he wrote in the letter given to TIME by his family members. "During the day, soldiers and police would get in two straight lines, and we would have to run in between them as they beat us with rocks and sticks. The officers stripped off our pants and shirts as they beat us with clubs. They put us in jail cells with what must have been 60 other inmates, and it was terribly hot and water was not made available to us. I saw an inmate suffer a heart attack right before my eyes and not receive proper medical attention."

He gave a harrowing account of his first few hours in jail, saying: "We were taken to a police station and tossed into a room nicknamed 'The Fridge' which was a room without seats, benches, windows and lights. I was not allowed a phone call, nor any communication with a lawyer, with one guard quipping that he could get me anything I wanted - drugs, alcohol, prostitutes - just not due process."

The following morning, he continued, he was blindfolded and taken to a room where a man asked him questions about his family and reason for staying in Egypt.

"One officer sarcastically shared with a fellow officer that he was confused as to why they hadn't just shot us dead and that we hoped we would attempt to escape so they could hunt us like chickens and kill us," he wrote.

When asked about the allegations of abuse, Director of the International Relations Department at Egypt's Ministry of the Interior Brigadier Hatem Fathy told TIME that officials often keep an eye on these kinds of injustices.

"We continue to provide all appropriate consular assistance, which includes routine prison visits," Fathy stated. "We take any allegations of mistreatment seriously and investigate them to the fullest extent possible... The Egyptian government has several mechanisms for complaints of any ill-treatment by police or any other department of the government."

Soltan's father, who is a professor at Cairo University and a member of the Muslim Brotherhood, was also arrested in September.