MOSCOW (AFP) - Russian opposition leader Alexei Navalny announced on Sunday he had been elected president of the unregistered Popular Alliance party.

"I have been elected president of Popular Alliance. Thank you for your confidence," said the 37-year-old on Twitter.

The conference for the party, founded in 2012 by Navalny supporters, took place in a Moscow hotel where members voted in large majority for the protest leader.

Mr Navalny had previously said he wanted to keep his distance from Popular Alliance to boost its chances of becoming a registered party, but in July the Justice Ministry rejected its request.

The protest leader proved himself a force to be reckoned with after he came second to a Kremlin loyalist in mayoral elections in Moscow in September. He won 27 per cent of the vote on an aggressive anti-immigrant, anti-corruption platform.

After the mayoral election Mr Navalny said he was ready to lead Popular Alliance and again tried to have it registered.

"I hope the party will now be registered because if not it will be yet more proof that all the declarations from authorities that they allow the opposition to participate in elections are just empty talk," said Mr Navalny at the party conference, quoted by the news agency Interfax.

The protest leader first shot to prominence during anti-Putin rallies that shook Moscow in the winter of 2011-2012, but has since been embroiled in a series of legal battles.

Earlier this month Russian investigators moved to indict him in a fraud and money laundering case, after a separate five-year sentence on embezzlement charges was commuted to a suspended term.