Mikhail Prokhorov, one of Russia’s richest tycoons and the owner of the New Jersey Nets basketball team, said Monday he will run against Prime Minister Vladimir Putin in the March presidential election.

Prokhorov has been cautious not to cross Putin’s path in the past, but the billionaire may pose a serious challenge to Putin, whose authority has been dented by alleged widespread fraud during Russia’s Dec. 4 parliamentary election.

Putin’s party only won about 50 percent of that vote, compared to 64 percent four years ago, and the fraud allegations have allowed opposition parties to successfully mount massive anti-Putin protests in Russia.

On Sunday, President Dmitry Medvedev promised on his Facebook page that the alleged vote fraud will be investigated. But Putin’s spokesman, Dmitry Peskov, predicted Monday the probe will show that little vote fraud occurred and that it had no effect on the outcome of the ballot.

– Reported by the Associated Press