BUCHAREST (Reuters) - Romanian prosecutors said on Wednesday they had launched a criminal investigation against Calin Georgescu, the far-right frontrunner in last year's cancelled presidential election, over several accusations including promoting antisemitism.

The ballot was voided in December on account of suspected Russian interference in favour of Georgescu, a strong critic of NATO and Western support for Ukraine. Moscow denied the accusations of meddling in the election.

Prosecutors launched a criminal investigation following the cancellation amid accusations of wrongdoing ranging from campaign funding fraud and promoting antisemitism and hate speech to acts against the constitutional order.

On Wednesday, after questioning Georgescu for several hours, they said they were formally investigating him on accusations of forming an antisemitic organisation, promoting war criminals and fascist organisations, and communicating false information.

Georgescu, who has denied all wrongdoing, on Wednesday accused authorities of behaviour reminiscent of Romania's communist past.

"The communist Bolshevik system is continuing its heinous abuse," Georgescu said on his Facebook account.

"They are looking to invent evidence to justify stealing the election and to do anything in their efforts to block a new candidacy from me."

Around 100 Georgescu supporters gathered in protest outside prosecutors' headquarters in the capital Bucharest, shouting "national unity", joined by ultranationalist members of parliament.

RAIDS

Prosecutors also said on Wednesday they had raided 47 addresses of people and associations connected to Georgescu.

Among them was Horatiu Potra, a former member of the French Foreign Legion and military contractor in the Democratic Republic of Congo whose security firm provides bodyguards for Georgescu. Prosecutors said a large cache of weapons and hidden cash was found during the raid.

His communications team said in a post on social media that authorities had hauled Georgescu in for questioning on the day he had intended to submit his candidacy for a rerun of the presidential election, set for May.

"Where is democracy now, where are the partners who should defend democracy?" the post read.

Members of U.S. President Donald Trump's administration have sharply criticised Romania for annulling its election. U.S. Vice President JD Vance said the cancellation meant Romania does not share American values, while billionaire Elon Musk labelled the chief judge of the top court that annulled the vote a "tyrant".

"They just arrested the person who won the most votes in the Romanian presidential election," Musk said on his social media platform X on Wednesday, repeating false claims that Georgescu had been arrested. "This is messed up."

Georgescu has praised Romania's 1930s fascist leaders as patriots and martyrs and expressed admiration for both Trump and Russian President Vladimir Putin. He remains voters' top choice in opinion polls ahead of the May rerun, although it remains unclear whether he will be allowed to run at all.

Romania's Iron Guard was a far-right movement and party that was founded in 1927 and became known for political assassinations and violent antisemitism.

Under present-day Romanian legislation, promoting fascist leaders and Nazi, racist or xenophobic symbols are banned and carry a prison sentence, although cases only rarely made it to court prior to the voided election.

(Reporting by Luiza Ilie; editing by Gareth Jones and Mark Heinrich)