Ukrainian pilot Nadia Savchenko is being taken back to prison, her lawyer, Mark Feygin, has said.

"Nadia Savchenko is now being taken from the Serbsky clinic back to prison. The examination has been completed," he wrote on Twitter on Friday.

Savchenko was undergoing a psychiatric examination at the Serbsky Institute.

"We are now at the Serbsky Institute. Doctors tell us that the examination has been completed. Nadia has been taken to prison," Feygin told Interfax, adding that "Nadia was 90% declared sane."

Lawyer Nikolai Polozov, in turn, tweeted that the defense team was not allowed to see Savchenko at the Serbsky Institute.

It was reported earlier that Savchenko, a 31-year-old navigator, was fighting with the Aidar volunteer battalion in eastern Ukraine when she was captured by illegal armed units near the town of Schastia, a suburb of Luhansk, in June. It turned out on July 8 that Savchenko was kept at a detention facility in Voronezh, Russia. On September 24, she was brought to detention center No. 6 in Moscow. Investigators insisted that Savchenko had to undergo a psychiatric evaluation.

Savchenko denies her guilt and says she was abducted on the Ukrainian territory.

On October 27, the Basmanny Court of Moscow decided to extend the custody of the Ukrainian pilot until February 13, 2015.