Moscow, Russia - Russia on Thursday extended by three months the detention of Wall Street Journal reporter Evan Gershkovich, who was arrested in March on spying charges and has been held in a Moscow prison ever since.

"The time of detention has been extended by three months... Until November 30, 2023," a spokesperson for Moscow's Lefortovsky court said.

AFP was denied access into the courtroom for the hearing, which was held behind closed doors.

But AFP reporters saw the 31-year-old, handcuffed and wearing a checkered shirt and jeans, being escorted into the court by masked men.

Russia Is the US changing its nuclear force policy in response to Russia easing its own strike threshold?

After the hearing, one of Gershkovich's lawyers left the court without giving any comment to journalists.

Gershkovich was arrested during a reporting trip in the Urals city of Yekaterinburg on March 29, becoming the first Western journalist to be arrested on espionage charges in Russia since the Soviet era.

Russia has not provided public evidence of the accusations and the legal proceedings have been classified as secret.

He has since been held in Moscow's notorious Lefortovo prison, famous for keeping inmates in near-total isolation.

US President Joe Biden has called for Gershkovich's release, but his administration admitted in July that there was still no clear "pathway" to getting the reporter home, despite high-level talks.