Britain has impounded a private jet it suspects of being linked to a Russian oligarch, and tightened aviation sanctions against Russia in response to the invasion of Ukraine. Transport Secretary Grant Shapps said Wednesday the Luxembourg-registered plane had been seized at Farnborough Airport in southern England while U.K. authorities tried to unravel its ownership. Read:New Zealand passes Russia sanctions bill U.K. officials believe the Bombardier Global 6500 jet is connected to billionaire oil tycoon Eugene Shvidler. It arrived in the U.K. from New Jersey last week and had been due to fly to Dubai on Tuesday. Britain has banned Russian-owned or operated planes from its airspace, but Shapps said the government was still working to close some “loopholes.” The government announced late Tuesday it was toughening sanctions to include “the power to detain any aircraft owned by persons connected with Russia.” Britain also banned the export of aviation- or space-related items and technology to Russia.