Sanctioned Russian oligarch Roman Abramovich must be investigated over the £1bn he could owe, a group of MPs has urged HMRC.
In a letter to the tax authority, Joe Powell, a Labour MP who leads a Parliamentary group on fair taxation, refers to BBC reports raising questions about whether tax is due on offshore investments.
"Proper investigation of these matters is essential," the letter said. HMRC said it was "committed to ensuring everyone pays the right tax under the law, regardless of wealth or status".
Mr Abramovich's lawyers have told the BBC he "always obtained independent expert professional tax and legal advice" and "acted in accordance with that advice".