A massive fire on a Russian warship was set by a saboteur fighting against his own country, Ukraine says

• Ukraine's military intelligence said that a saboteur was responsible for damage to a Russian ship.
• The Serpukhov was set ablaze in April, damaging much of its interior, officials said.

A Russian dissident covertly working with Ukrainian military intelligence was responsible for setting a fire that badly damaged a Russian warship, Ukrainian officials said on Wednesday.

Ukraine's Main Intelligence Directorate, or HUR, said at a press conference that a Russian sailor with the callsign "Hoga" had set the blaze aboard the missile ship Serpukhov in April, .

They said the ship, based out of the Russian exclave of Kaliningrad on the Baltic Sea, needed extensive repairs after the fire.

In April, Ukrainian intelligence announced that the Serpukhov had been damaged by a fire, without explicitly claiming responsibility.

The HUR said that the ship's communication and automation systems had been damaged. It shared a brief video clip of a fire starting inside a cabin, as well as diagrams.

Russian authorities did not comment at the time.

In a statement at Wednesday's press conference, Ukraine's "Freedom of Russia" legion — which consists of dissident Russians who fight on Ukraine's side — said that the fire was started by one of their recruits.

Hoga, an active serviceman in Russia's Baltic Fleet, contacted Ukraine's "I Want To Live" program in 2023, Radio Svoboda reported the HUR as saying.

The program, which has been in operation since late 2022, provides a secure phone line for Russians to call to arrange to surrender.

Ukraine claims that more than 220 soldiers have surrendered in this way.

Hoga covertly joined the "Freedom of Russia" legion, remained on board the Serpukhov, and passed intelligence onto the HUR at risk to his own life, the legion said in a statement.

He then committed the act of sabotage on the ship before escaping to Ukraine with secret documents, the HUR said.

Business Insider was unable to independently confirm the claims.

The Serpukhov is one of Russia's most advanced missile ships, Ukrainian intelligence said.

According to KCHF, a Russian site that closely monitors Russia's Black Sea Fleet, the Serpukhov is capable of striking land targets with cruise missiles and previously served in the Black Sea, before being transferred to the Baltics in 2016.