Alexej Navalny reported for the first time in an interview from the Russian prison camp.
He also describes details from camp life.
Moscow - Kremlin critic Alexei Navalny was sentenced to several years in prison in a Russian prison camp in February.
Now the 45-year-old has reported from his detention for the first time in an interview and complained about his detention conditions.
Putin opponent Navalny reports from the prison camp: "You have to sit on a chair and watch the television"
He would be forced to watch state television and propaganda films for hours every day, the 45-year-old said in an interview with the US daily "New York Times", which published excerpts from it on Wednesday.
Reading or writing is forbidden during this time.
"You have to sit in a chair and look at the television."
A total of 54 handwritten pages with Navalny's answers are said to have reached the journalists.
His press spokeswoman Kira Jarmysch confirmed on Twitter that this was the first interview since his incarceration in the Pokrov camp around 100 kilometers east of Moscow.
Navalny: "Putin regime a historic accident"
Navalny is considered the fiercest opponent of Russian President Vladimir Putin.
He was sentenced to several years in prison in February for allegedly violating probation conditions in a previous criminal case while he was recovering from an assassination attempt in Germany.
The judgment has been criticized internationally as politically motivated.
There is now a new charge that could extend his detention.
In an interview with the New York Times, the opposition politician again called for tough sanctions against Russian oligarchs who support Putin.
The EU and US punitive measures should not affect ordinary Russian people.
"The Putin regime is a historic accident and not a legality," wrote Navalny in a response to the journalists, according to the newspaper. "Sooner or later this mistake will be corrected and Russia will take a democratic, European path."
(Rjs / dpa)