The deputy editor-in-chief for Russia's leading news radio station has been stabbed by an unknown attacker, said the company.

Tatyana Felgenhauer was stabbed in the throat by an unknown attacker who burst into the studios of Ekho Moskvy, often been described as Russia's only independent news radio station.

Felgenhauer is best known for co-hosting a popular morning show.

She has been rushed to hospital but there are varying reports of her condition circulating around Russian media.

The state-run TASS news agency cited an unnamed hospital source as saying the editor is in a grave condition.

But Alexei Venediktov, the editor-in-chief of Ekho Moskvy, tweeted that Felgenhauer has been taken to hospital and her life is not in danger.

He added that security guards at the station had detained the man, who has been handed over to police.

The state-run RIA Novosti news agency quotes an unnamed source as saying that the knifeman may have had personal motive for the attack, while Interfax news agency said Felgenhauer knew her assailant and that the confrontation was not connected to her journalism.

The spokesman for the Russian Prosecutor General's Office described the attack as "outrageous" and said prosecutors are committed to investigating the case closely.

Ekho Moskvy's searing criticism has angered many in the Russian government, and its hosts and journalists have reported death threats previously.

Another popular Ekho Moskvy host, Yulia Latynina, fled Russia in September following a suspected arson attack on her car.

The deputy editor-in-chief for Russia's leading news radio station has been stabbed by an unknown attacker
The deputy editor-in-chief for Russia's leading news radio station has been stabbed by an unknown attacker Reuters
The editor-in-chief of Echo published this photo of the alleged attacker.