It has become a sinister symbol marking support for Russia's barbaric invasion of Ukraine. First seen on tanks and armoured vehicles on the battlefield, the letter Z has since been adopted for propaganda purposes by Vladimir Putin's supporters back home. It has appeared on cars, clothing and signs and in images such as a sick photo of a Z reportedly made by Russian soldiers from the badges of Ukrainian troops killed in action. Russian gymnast Ivan Kuliak, 20, is facing disciplinary action