DW: Your first few days in prison in September 2016 were widely reported: You were beaten, shackled and your head was forced into a toilet. You were threatened with rape. You said the torture "broke" you.

Ildar Dadin: After that, I followed the prison rules. I stopped fighting for my rights. I didn't complain about anything and I followed instructions blindly.

What kind of instructions?

My difficult prison conditions were extended. For example, I was accused of cursing at the prison authorities, refusing to eat or not getting up immediately for the bell. All lies, but I admitted to everything. When you are brought to a cell, you have no idea it is punishment. You go to the prison authorities and have no chance to prepare or defend yourself. You don't want to fight when you know what the torture is. You agree to anything when the lies are on camera. If asked if you have questions, the answer is: No questions! Once I cautiously said I wanted to invoke Article 51 of the Russian Constitution (the right to not self-incriminate) and not sign the measure. As a result, I was taken to the prison yard and left in the cold and dark for two hours. I was afraid I would be tortured again so agreed to everything.

How did they torture you?

It was not possible to be in a normal prison block where other inmates are housed. In all, I spent 45 days in solitary confinement. Severe conditions were imposed on me. My cell differed from solitary confinement only in that there was a table for personal items and that you don't spend 15 days there, but 6 months, and there were other inmates there.

What did you do all day?

I walked in circles in the cell and counted my rounds. I memorized the six pages on the wall that detailed the prison conditions. Twice a day, the prison rules were announced over a loudspeaker in a scratchy, monotone voice. I would wash up between 7:30 and 8, but you can't do so until the time is up. You have to take the rag with you and clean the floor again. I first asked how you know when the time is up because there were no clocks in the prison. I was told it's when the music from the Russian band, Lyube, gets played. Their patriotic songs were played mornings and evenings during inspections. Through the music, I could hear beatings and screams from other cells.

Every time?

No. Mostly when there was a new inmate. You could tell they were new, because you could hear their hair being cut. Normally everyone had their heads shaved on Saturdays. So if it wasn't a Saturday, you knew someone new had arrived. And you also knew that you would hear them being beaten the next day.

How did you occupy your time in prison?

I listened to the radio during the week. There were no books for the first 40 days, but then a human rights activist came to check on things and I was offered access to the library.

Tell me about your cellmates.

I liked the first one in the beginning. Then I realized he was crazy. A normal person doesn't constantly curse when there for just one or two months. Why violate the prison rules especially when it would surely lead to beatings? He would throw away entire rolls of toilet paper. He once smeared the wall next to the toilet with feces. He talked to himself all the time, and he would make strange sounds – like someone was beating him -- until he fell asleep. I'm sorry – perhaps he was constantly beaten. I don't know. My next cellmate was there for rape. We got along normally at first, but then things got tense. I said that each person should only use his own things, but he would always come to take my things and insult me. I think the prison authorities intentionally set up a confrontation. I made the futile request for a cell change. Then we got into a fight the next day. The third inmate was a Greek, and we were together for about a month. He was serving time for financial crime. We didn't have major problems with each other. I believe he wished me well in his own way.

Dadin, 34, served 15 months of his three-year prison sentence beginning in 2015. He was convicted of multiple violations of the public gathering ban. His protests in Moscow were against the war in Ukraine, among other things. Dadin was the first person to be charged using this controversial new law, adopted in 2014. It has been interpreted as a ban on peaceful protest, as well. Dadin's imprisonment was internationally criticized. Russia's supreme court ordered Dadin's release.

The interview was conducted by Yulia Vishnevetskaya.