Ukraine's security service said it had launched a criminal probe after a non-functioning "technical device" was found in an office that could have been used in the future by the country's commander in chief Valery Zaluzhniy, Paralel.Az reports citing Reuters.

It said an investigation had been opened under an article in the country's criminal code on "unlawful acquisition, sale, or use of special technical means for obtaining information."

The device was "in a non-operational state", it said and stressed that it was not found in Zaluzhniy's office.