KYIV, May 12 – The office of the Prosecutor General said Wednesday it will seek to detain pro-Russian opposition leader Viktor Medvedchuk to keep him in custody while investigating his suspended transfer of sensitive military information to Russia.

Medvedchuk visited the office earlier on Wednesday, a day after teams of security agents have searched his house in Kyiv, unsuccessfully trying to locate him in order to charge him.

The charges of treason carry potential sentences of up to 15 years.

Medvedchuk left the office of the Prosecutor General after reading the charges, and said he is prepared to defend himself in court. He also said the prosecutors did not stick to proper legal procedures while officially charging him, and said the charges were politically motivated.

"I read the charges together with my lawyers, but I was not handed the charges according to the legal procedures,” Medvedchuk said after leaving the office.

“I can say that the accusations and incriminations of a number of articles, including serious ones, of the Criminal Code of Ukraine are unfounded, unproven,” he said. “And all this in general can be called nothing more than politically motivated actions of prosecutor's office in relation to me.”

Medvedchuk reiterated that he was not going to leave Ukraine.

Prosecutor-General Irina Venediktova said Tuesday that charges under several articles were brought against Medvedchuk business partner Taras Kozak.

Medvedchuk is accused of transferring oil and gas production licenses from one of the fields in Crimea to Russian authorities; Russia annexed Crimea in 2014.

Medvedchuk is also charged with disclosing secret data on the deployment of Ukrainian military unites last year.

The developments come weeks after tensions between Kyiv and Moscow over a build-up of Russian troops on Ukraine's eastern border and rising clashes in eastern Ukraine. The Kremlin has sharply criticized the crackdown on Medvedchuk.

The 66-year-old heads the political council of the pro-Russian opposition party Opposition Platform - For Life. It is the largest opposition group in the parliament, with 44 of the 450 seats.

He has close personal ties with Putin, who is the godfather of Medvedchuk’s daughter.

The new charges are part of a broader campaign against Medvedchuk launched by authorities in February, when his financial assets were frozen for three years. In February, authorities also shut down three pro-Russian TV channels, 112, Zik and NewsOne, which Medvedchuk controlled. (tl/ez)