The US and UK are reportedly reviewing more than $20 billion worth of cryptocurrency transactions that passed through a Russia-based virtual exchange. This is part of allied efforts to crack down on sanctions evasion that is believed to be supporting Vladimir Putin’s war in Ukraine. The payments under scrutiny went through Moscow-based crypto exchange Garantex using the dollar-pegged cryptocurrency Tether. The transfers have taken place since Garantex was sanctioned by the US and UK on suspicion of enabling financial crimes and illicit transactions in Russia.