Ukraine's security services announced the arrest of Russian President Vladimir Putin's closest associate in the country -- tycoon and opposition figure Viktor Medvedchuk.

Medvedchuk's capture was first revealed by Ukrainian President Volodymyr Zelenskiy, who shared a photo of the suspect on social media, sullen, in handcuffs, and attired in military garb with a Ukrainian flag patch. 

"Ukraine's security service conducted a special operation. Congratulations on your accomplishments," Zelenskiy said on Telegram, later suggesting that he would be exchanged for Russian POWs in Ukraine.

In a Telegram video message, Zelensky proposed to the Russian federation to exchange Medvedchuk with the Ukrainians who are held captive in Russia.

Officers uncovered a copy of a classic Pullman railway carriage, elaborately adorned with golden fixtures, situated at a mock-up of a railway station, all disguised beneath a tarp, at Medvedchuk's property.

However, it was unclear where and how he was apprehended right away. The Head of the Security Service Unit (SBU), Ivan Bakanov, congratulated his investigators and counterintelligence agents for demonstrating their competence and conducting a rapid and risky multi-level special operation to seize deputy Medvedchuk.

"You have the option of evading justice. You can even disguise yourself by wearing a Ukrainian military uniform, but will this help you avoid consequences? Not in the least," the SBU expressed its displeasure with the situation on Twitter.

Medvedchuk became wealthy as a result of his Russian energy holdings and ties to the Kremlin.

His union, Opposition Platform For Life, promoted a pro-Moscow agenda until he was arrested for treason in May 2021, charged with selling classified information to Russia and plundering the natural resources of Crimea when it was occupied by Russia.

He had been under house arrest and denied the allegations before escaping during the war's early days. The Royal Romance, a 93-meter yacht worth $200 million, was confiscated in the Croatian port of Rijeka last month.

In January, the U.S. imposed fines on Medvedchuk and three other Moscow-backed Ukrainian officials, accusing them of plotting to establish a confederate administration in the aftermath of the Russian incursion.

In March, Zelenskiy outlawed Medvedchuk's organization, Ukraine's main opposition group, as well as many other smaller pro-Russian political groups.

The raid on Medvedchuk in Kyiv enraged the Kremlin, with Putin pledging to react to what he deemed political persecution at one point.

Dmitry Peskov, the Kremlin's spokesperson, refused to respond to Medvedchuk's arrest.