Ukrainian security services on Monday published a video showing Viktor Medvedchuk, a detained pro-Russia Ukrainian tycoon and politician, calling to be exchanged for Ukrainian forces fighting in the besieged port city of Mariupol. This undated and unlocated handout picture released on April 12, 2022 by the Security Service of Ukraine shows business tycoon Viktor Medvedchuk with his hands in cuffs and dressed in a Ukrainian army uniform. Photo: AFP "I want to ask Russian President Vladimir Putin and Ukrainian President Vladimir Zelensky to exchange me for Ukrainian defenders and residents of Mariupol," he said in the video, wearing black clothes and looking directly into the camera. But Russian state TV broadcast a video Monday of what it described as "Britons" captured fighting for Ukraine demanding that Prime Minister Boris Johnson negotiate their release. The two haggard-looking men shown in the video asked to be exchanged for Viktor Medvedchuk, a wealthy Ukrainian businessman close to President Vladimir Putin, who was recently arrested in the pro-Western country.