KIEV, October 3. /TASS/. Ukraine’s Foreign Ministry has voiced a strong protest to Moscow over the arrest of Ukrainian journalist Roman Sushchenko on suspicion of espionage.

The detention of Sushchenko, a reporter of the Ukrinform news agency in France, by Russia’s Federal Security Service (FSB) on September 30 was "groundless," the ministry said demanding his "immediate release and unhampered return home."

The ministry also called on Russia to respect the Ukrainian citizen’s rights and to immediately allow Ukraine’s consular staff members to visit him.

Russia’s FSB earlier said that Col. Sushchenko, a staff member of the main intelligence department of Ukraine’s Defense Ministry, was detained in Moscow "while on a spy mission."

The FSB said Sushchenko collected secret information on Russia’s Armed Forces and the National Guard and the disclosure could have undermined Russia’s defense capabilities.

Lawyer Mark Feigin earlier told TASS that his client came to Moscow on vacation to visit his relatives.

Sushchenko has been arrested until November 30. A criminal investigation into espionage has been launched.