The jailed former executive director of the pro-democracy Open Russia movement, Andrei Pivovarov, has been charged with heading an "undesirable" organization, an accusation that stems from a six-year-old law that has repeatedly been used to target critical voices.

Pivovarov's team said on Telegram on October 11 that the charge stemmed from 30 posts on his Facebook account and one repost.

In some of the posts in question, Pivovarov allegedly spoke negatively about employees of the Federal Security Service (FSB), criticized police actions, and supported protesters.

If convicted, he faces up to six years in prison, according to his team.

Pivovarov, who has denied any wrongdoing, was detained after being removed from a Warsaw-bound plane just before takeoff from St. Petersburg in May.

He is being held in pretrial detention.

Leaders of the Russian-based Open Russia dissolved the group in late May after authorities designated it an "undesirable" organization.

They said they did so to protect supporters from further "harassment" by the Russian authorities.

Open Russia was financed by Russian tycoon Mikhail Khodorkovsky, who moved to London after spending 10 years in prison in Russia on charges widely seen as political revenge for challenging President Vladimir Putin politically.

The "undesirable organization" law, adopted in 2015, was part of a series of regulations pushed by the Kremlin that squeezed many nonprofit and nongovernmental organizations that received funding from foreign sources -- mainly from Europe and the United States.