French writer and journalist Anne Nivat will be allowed to return to the country after being expelled over problems with her visa as the decision to do so was out of proportion, the head of the Federal Migration Service said Thursday.

"I studied the case and concluded that the decision … was groundlessly harsh. I believe that the decision to shorten her stay will be cancelled," Konstantin Romodanovsky told reporters.

He added that Nivat could return immediately. "Your colleague can already now, in principle, enter the Russian Federation."

Nivat was detained and had her visa canceled last week while researching a book in Vladimir, east of Moscow. The official reason given was that she was doing journalistic work while in the country on a business visa.

Migration service officials told her that she was "speaking with the opposition" instead of doing business. Nivat had been interviewing politicians, including opposition party members, in Vladimir and in the northwestern region of Karelia.

She left the country Sunday.

But in a sign that her treatment was not approved by everybody in Moscow, the head of the migration service in the Vladimir region was fired Tuesday.

Romodanovsky said he had relieved the official of his duties because he had made the wrong decision. An internal investigation into the case is ongoing.

Nivat, a former correspondent for the Liberation newspaper who wrote an acclaimed book on Chechnya in 2000, said she suspects the decision was linked to authorities' nervousness in the run-up to the March 4 presidential election.

She wrote on Facebook that she viewed the decision with caution. "The moment of truth will be when I will reapply for a visa," she said.