Anton Bakov, a businessman and the founder of Russia's Monarchist Party, said the project involved setting up the capital on Malden Island, where he planned to build hotels.
The proposed empire also included Caroline Island and Starbuck Island.
Mr Bakov, who used to be a parliamentarian, visited Kiribati last year, and claimed the government had approved the establishment of the empire on its territory.
He has reportedly also been in talks with Montenegro to get land for a royal state.
