A Russian political party leader claims he purchased the Cook Islands bird sanctuary Suwarrow from the government there in July.
Anton Bakov has declared Suwarrow the capital of a revitalised Russian empire and himself the prime minister.
Izvestia in Moscow quotes Mr Bakov as saying he bought Suwarrow for tens of millions of dollars from Prime Minister Henry Puna.
But Mr Puna says the claim is preposterous.
The island is small and uninhabited.