The British are looking for helicopters and planes belonging to sanctioned Russian businessmen and have asked the Isle of Man authorities to de-register the personal helicopter of Chelsea Football Club owner Roman Abramovich, Reuters reported, citing a transport ministry source.

Abramovich is among seven entrepreneurs who were hit by British sanctions on Thursday, meaning his assets, mostly real estate, private jets and helicopters, will be frozen and no financial deal can be made against them.

The sanctions also cast doubt on Abramovich's plans to sell Premier League club Chelsea, effectively placing reigning European champions under state control. The team may continue to play, but the government says it is open to selling the club if Abramovich does not benefit.

According to him, the transport minister has asked the Isle of Man, a self-governing territory under British sovereignty, to de-register Abramovich's personal helicopter, which currently bears the registration number M-HELI.

The Isle of Man, which maintains its own aviation registry, has already deregistered eight Russian-linked aircraft.

Britain said on Wednesday it had seized a plane linked to a Russian billionaire close to Abramovich under new aviation sanctions that give authorities the power to detain any Russian aircraft and ban the export of aviation or space goods to Russia.