Russian President Vladimir Putin says he knows nothing about the fact that Natalya Sharina, the director of the Moscow-based Ukrainian Literature Library, has been under house arrest for nearly two months and promised to look into the matter.

"It's the first time I've heard about [Sharina's] detention and house arrest. I simply cannot comment on this, because I don't know what it's all about," Putin said at a session of the presidential culture and arts council in response to literary critic Alexander Arkhangelsky's remark.

Arkhangelsky asked the president to address the case in which Sharina has been accused of the circulation of extremist literature and placed under house arrest.

On October 28, Sharina was "placed under house arrest, as if she were a dangerous criminal, and she can't even go out for a walk," Arkhangelsky said.

"We know stories of other people who were placed under house arrest and who did shopping and composed songs about pink slippers during that. I am not an investigator and haven't seen the case materials, but is she really such a horrible monster that she must be put under house arrest? The case has been dragging on since 2010. It was being investigated calmly, but then everything broke loose. And the matter is not only about the fate of a 58-year-old woman, who has never stood trial and who has never been engaged in business or politics, but also about the fate of the library as a whole," he said.

Putin promised to look into the matter.