Last summer saw the brief arrest of investigative journalist Ivan Golunov on falsified charges, a move that his supporters said was punishment for his work. He was released days later following widespread public outcry. Weeks later, an unprecedented wave of opposition protests was met with thousands of protesters briefly detained and at least a dozen activists criminally charged in the so-called “Moscow Case.”

More than half of Russians believe that their country imprisons people for political reasons, an all-time high since the independent Levada Center polling agency first conducted the survey in 2004.

Sixty-three percent of Russian participants responded affirmatively when asked whether Russia has political prisoners, an increase from 50% of respondents the year before, Levada’s survey published Monday said.

This increase can be linked to the controversy surrounding the Golunov case as well as to the arrests of opposition protesters in the “Moscow Case,” Levada Center Director Lev Gudkov told the Vedomosti business daily.

Respondents were most likely to name exiled former oligarch Mikhail Khodorkovsky and Ukrainian film director Oleg Sentsov as the political prisoners they recognize, Gudkov added.

The Memorial human rights organization has recognized 64 people on its list of Russian political prisoners. The organization lists another 250 people who have been imprisoned for their religion.

Levada conducted the survey among 1,608 adults living in 50 Russian regions between Dec. 12-18.