A British businessman has been charged with conspiring to violate sanctions imposed by the US government on a Russian oligarch. The US Department of Justice (DoJ) said Graham Bonham-Carter was arrested on Tuesday after being accused of funding properties purchased by Oleg Deripaska and expatriating his artwork, which Bonham-Carter denies. The DoJ said the US government would be seeking Bonham-Carter’s extradition. Deripaska was initially sanctioned by the US for “having acted or purported to act on behalf of, directly or indirectly, a senior official of the government of the Russian Federation, and for operating in the energy sector of the Russian Federation economy”. Bonham-Carter, the cousin of the actor Helena Bonham Carter, is accused of engaging in more than $1m (£900,000) of illicit transactions to fund real estate properties in the US for Deripaska’s benefit, in an investigation conducted with “substantial assistance” from the UK’s National Crime Agency. It is alleged the businessman was instructed by Deripaska to set up a company, named GBCM Limited, for managing his properties, including two in New York City and one in Washington DC. The DoJ said money was sent from a GBCM Limited account in Russia to pay for staff salaries and property taxes and to maintain the oligarch’s properties. Bonham-Carter faces three charges – conspiring to violate and evade US sanctions in violation of the International Emergency Economic Powers Act (IEEPA), one count of violating IEEPA and one count of wire fraud. Each charge carries a maximum sentence of 20 years in prison. Deripaska was one of seven oligarchs hit with sanctions by the UK on 10 March, when it described him as being “closely associated” with both the Russian government and its leader, and “involved in destabilising and threatening” Ukraine. Four days after the sanctions were imposed on the industrialist, four protesters broke into one of his properties in Belgrave Square in London before declaring it “belongs to Ukrainian refugees”. Bonham-Carter had his bank accounts frozen for six months at Westminster magistrates court in March after it was alleged they contained money linked to Deripaska. Deripaska founded the Rusal aluminium company and is considered an ally of the Russian president, Vladimir Putin. His wealth has been estimated to be more than £2bn.