Ukrainian investigators said Tuesday that a prison official in the recently liberated city of Kherson was suspected of committing treason for releasing inmates before the Russian army's retreat.
On Nov. 11, the Russian army pulled forces from the southern city of Kherson, in a major setback in a region President Vladimir Putin claimed to have annexed.
On Tuesday, Ukraine's State Bureau of Investigation (SBI) said that an official in charge of security at a local prison collaborated with the Russian forces and allowed inmates to flee ahead of Russia's retreat.
"The SBI detained a traitor from the Kherson colony, who released prisoners before the liberation of the city," it said in a statement.
"On the day Kherson was liberated from the occupiers, the colony employee pretended not to notice the escape of the prisoners and did not take any action to prevent it."
He himself did not have the time to escape and was detained, the SBI added.
The former employee is suspected of committing state treason and could face up to life in prison.
Last week, Ukraine said it had detained a Russian serviceman wearing civilian clothes in recaptured Kherson, who was pretending to be a local but later admitted to being a professional soldier.
Ukrainian authorities and witnesses say that the Russian troops have left a trail of misery and destruction upon their retreat from Kherson.
On Monday, Kyiv authorities said four Russian torture sites had been discovered in the city.