"Yes, repeatedly," Assistant US Attorney Norman Barbosa stated on Friday when asked whether Seleznev's spouse was offered protection by the US authorities.
Barbosa noted that Otisko left the United States within days after discussing her possible testimony with the authorities.
US Attorney for the Western District of Washington Annette Hayes said that prosecutors do not know where Otisko is and what had happened to her.
"That is an issue we are very concerned about, that she was somebody who… could have been a very important witness in the case," Hayes remarked.
Earlier on Friday, US Judge Richard Jones has sentenced Seleznev to 27 years in prison. Seleznev’s arrest in the Maldives in 2014 and extradition to the United States was criticized by the Russian Foreign Ministry, which characterized his detention as kidnapping and conducted against all norms of international law.