Former commander of Russian paramilitary group Wagner Andrei Medvedev, who fled to Norway ten days ago, was arrested by Norwegian police under immigration law.
The exact reasons for the arrest were not specified, but his lawyer said it was due to "violations of safety regulations" surrounding him.
Medvedev, 26, had crossed the Russian-Norwegian border in the far north in the night between 12 and 13 January asking for asylum in the Scandinavian country, saying he was ready to "speak about his experience in the Wagner group to people investigating the crimes of war".
He said he fought for Wagner in Ukraine for four months before defecting in November when the paramilitary organization led by Yevgeny Prigozhin allegedly extended his contract against his will.
A potentially valuable witness to shed light on the brutality of the paramilitary group in Ukraine, Medvedev has been grilled by the Norwegian authorities since his arrival in the country, in an undisclosed location and under close surveillance.
"He was arrested under immigration law and the possibility of internment is being considered," Jon Andreas Johansen, a police official in charge of immigration affairs, told AFP in an email.
Police declined to specify the exact reasons for his arrest, or provide further comment.
His lawyer, Brynjulf Risnes, said that Medvedev was arrested because he refused to comply with all the security rules imposed on him.
"He thinks it's necessary," he said.
"Naturally many security measures have been taken and it is difficult for him to respect them. He is not accused of
anything," added the lawyer.
Many questions remain about the figure of Andrei Medvedev, his past and the circumstances of his escape.
Many experts believe the former mercenary could not have crossed the highly guarded border without assistance.
He himself claims to have crossed the Pasvik, the frozen river that marks the border between Russia and Norway, on foot after being chased by Russian guards with dogs.
The
Norwegian police crime squad (Kripos), which participates in the international investigation into war crimes in Ukraine, began questioning him on Saturday.
Risnes said he cooperated.
AFP has been unable to independently confirm the veracity of his statements.
On the other hand, the head of the Sitting Russia charitable foundation Olga Romanova said the Wagner group had already lost about 40,000 prisoners previously recruited in the war in Ukraine.
In a televised interview, Romanova said the mass abandonment of prisoners from "Wagner" began in the autumn and many fled from the front to Russia, taking their weapons with them.
Romanova expressed the assumption that Prigozhin himself does not keep track of the missing and deserters among the mercenaries - all are recorded among the dead.
This is probably indicated by the fact that relatives of the dead in Russia are given empty coffins.