The court ruled on January 30 that Chanysheva, whose pretrial detention expires on February 3, will remain in custody at least until April 3.
The 40-year-old activist was arrested in Ufa in November 2021 and later transferred to a detention center in Moscow.
Chanysheva headed the local unit of Navalny’s network of regional campaign groups until his team disbanded them after a Moscow prosecutor went to court to have them branded “extremist.”
The court accepted the prosecutor’s request, effectively outlawing the group.
Chanysheva’s defense team said at the time that her arrest was the first since the movement was banned. The charges appear to be retroactive, since the organization she worked for disbanded before it had been legally classified as extremist.
International and domestic human rights groups have urged Russian authorities to release Chanysheva, saying that the extremism charges are absurd and should be dropped.
Navalny himself has been in prison on charges he and his supporters call politically motivated since February 2021.
Several of his associates have been charged with establishing an extremist group. Many of them have left the country.
Several former activists who worked for Navalny’s groups fled the country shortly before and after Chanysheva’s arrest.