Ukraine said Monday the former head of the SBU security service in northeastern Kharkiv will go on trial on high treason charges for allegedly sabotaging the region's defense against Russia.

The State Bureau of Investigation said on Telegram that the former official faces life imprisonment.

The law enforcement agency alleged that Roman Dudin, 40, "instead of organizing work to counter the enemy... actually engaged in sabotage."

Most of the northeastern region of Kharkiv, which borders Russia, was occupied by Moscow troops from the start of the Russian invasion in February last year until September.

Dudin believed the "offensive would be successful" and hoped new Russian authorities would treat him favorably due to his "subversive activities," the State Bureau of Investigation said.

He is accused of leaving his post without permission while under martial law and illegally ordering his staff to leave work and quit the region.

In addition, he is accused of "deliberately creating conditions" enabling Russian troops to seize weapons and protective equipment from the security service's headquarters.

The case is due to go to trial.

Dudin held the post from 2020 until May 2022, when he was sacked by President Volodymyr Zelenskyy, who said he "did not work to defend the city in the first days of the invasion and only thought of himself".

Zelenskyy then fired SBU chief Ivan Bakanov in July, saying over 650 cases were being investigated of security officials suspected of committing treason and aiding and abetting Russia.

In Ukraine's southern Kherson region – also occupied by the Russian army at the start of the war – an SBU official is suspected of having shared with Russian troops top secret maps of minefields intended to hamper their advance.