The man, whom prosecutors did not name, allegedly passed sensitive details about the results of artillery and rocket attacks on Kyiv and surrounding area to an intermediary of the Russian defence ministry.

"In addition, he repeatedly provided the enemy with detailed information about the positions, numbers and routes of the Ukrainian Defence Forces, as well as the location of checkpoints, engineering fortifications and weapons depots in the Kyiv region," the prosecutor's office said.

"He was sentenced to 15 years in prison with confiscation of property."

Ukraine has prosecuted and investigated thousands of people it accuses of having collaborated with Russian forces since they invaded in February 2022, many in the east and south of the country.

The United Nations said last year Kyiv had opened more than 6,600 criminal cases "against individuals for collaboration and other conflict-related crimes" since the war began.