A Russian journalist from investigative newspaper Novaya Gazeta was released Monday, having been detained overnight in the Donetsk region in eastern Ukraine.
Correspondent Pavel Kanygin made contact with the editorial office after hours of uncertainty about his whereabouts, said a message published on the Novaya Gazeta website.
Kanygin was captured overnight in the eastern city of Artemivsk by unknown assailants and taken to Slovyansk, Ekho Moskvy said.
The journalist had earlier highlighted on his Facebook account several shortcomings in the organization of a referendum on self-rule for eastern Ukraine, which was held Sunday in the Donetsk region.
Correspondent for Ekho Moskvy, Ilya Azar, said Monday on his Twitter account that he had received a text message from Kanygin saying: "I have been kidnapped, call Moscow."
Azar said in the Twitter message that he had paid $1000 to facilitate Kanygin's release.
Eastern Ukraine has seen several kidnappings in recent weeks, with a team of OSCE observers and several Western journalists having been taken hostage by separatist militants.