A Russian court on Tuesday denied an appeal by US dual citizen journalist Alsu Kurmasheva against her pre-trial detention on charges of allegedly failing to register as a "foreign agent".

Kurmasheva is the second US journalist to be arrested in Russia this year after Wall Street Journal reporter Evan Gershkovich was detained in March for "spying" - a charge that he and his employer vehemently deny.

"(Kurmasheva) and her lawyer asked to change the measure of restraint from detention to house arrest. The court disallowed the appeal," a representative from the Supreme Court of Tatarstan told the Interfax news agency.

Kurmasheva, who works for the US-funded Radio Free Europe/Radio Liberty (RFE/RL) media outlet, was detained by Russian law enforcement in the central city of Kazan earlier in October.

A court last week ruled to keep her in pre-trial detention until at least December 5 for the charge of failing to register as a "foreign agent", which carries a potential five-year prison sentence.

Her employer has called for her immediate release.

Rights groups have warned her detention marks a new threshold in Russia's campaign against independent media, which has escalated dramatically since Moscow's offensive in Ukraine.