A probe has been launched in the southern Russian city of Krasnodar into allegations of ballot stuffing at a polling station during the December 4 parliamentary elections, investigators said on Friday, according to RIA Novosti.

The investigation is the first since the end of the polls, which were marred by multiple allegations of electoral fraud in favor of Prime Minister Vladimir Putin`s United Russia party.

The probe was launched after a complaint by a candidate from the nationalist LDPR party, who said he had seen almost 100 ballots "folded up, as if they had been placed there simulteneously" when the ballot box was opened. He also said all the ballot papers were marked for United Russia.

Russia’s independent election monitoring organization Golos said it had logged more than 7,000 cases of falsifications during the polls.

International observers from the Council of Europe and the Organisation for Security and Co-operation in Europe reported “flagrant procedural violations” and "several serious indications of ballot box stuffing."

The probe comes a day after Putin told Russians in a televised Q&A session that web cameras should be installed at polling station ahead of the March presidential elections, in which he is due to stand.

But he dismissed allegations that the December 4 polls were invalid.

"As regards vote-rigging and the fact that the opposition are not pleased with the election results, there is nothing new here, this has always been the case," he said.

"The opposition is there to fight for power and is fighting for power. That is why it is seeking any opportunity to come closer to power, to edge the current authorities out, to accuse them, to point to their mistakes."