Far-right deputy PM faces probe after reports say his League party received millions of euros via covert Russian deal.

Italian prosecutors have opened an investigation into possible corruption involving Deputy Prime Minister Matteo Salvini following media reports that a covert Russian oil deal was devised to funnel millions of euros to his ruling League party.

Salvini, who serves as both deputy prime minister and interior minister in the government, has denied that his party received any money from Moscow.

Italian news magazine L’Espresso reported in February that Salvini’s former spokesman Gianluca Savoini had held talks in Moscow last October with Russian businessmen about a possible oil deal that would enable funds to be siphoned to the League.

Savoini denied the allegations at the time.

The US website Buzzfeed said on Wednesday it had received an audio recording of the Moscow meeting and published a transcript where Savoini can be heard discussing a covert oil transaction.

The Italian deputy prime minister told local media on Thursday that he had met a group of unnamed businessmen but denies any wrongdoing and says the League did not receive any money from the Russians.

Two sources with knowledge of the case told Reuters magistrates opened their probe following the publication of the article in L’Espresso.

One of the sources said investigators were aware of the audio recording before Buzzfeed published its story.

Contacted by Reuters, Savoini declined to comment on news of the judicial investigation, which is being overseen by Fabio De Pasquale, who heads a team of magistrates pursuing international economic cases.

Italian law forbids parties from accepting donations from foreign entities and the opposition centre-left Democratic Party (PD) has demanded that Salvini appear in parliament to address the allegations.

The Senate speaker, who is a member of the League’s long-standing political ally Forza Italia, refused to summon Salvini, dismissing the controversy as “journalistic gossip”.

Like other far-right leaders in Europe, Salvini has looked to forge close ties with Russian President Vladimir Putin and has paid several visits to Moscow in recent years.

He has repeatedly denounced European Union economic sanctions on Russia and pledged to try to overturn them.

Putin visited Rome last week and praised Salvini, telling Corriere della Sera newspaper he was “in constant contact” with the League.

Tough financing laws in Italy aimed at stamping out years of corruption have left parties struggling to fill their coffers.

An Italian court last year gave the League 75 years to pay back some 49 million euros ($54m) it owes the state following a corruption trial involving its previous chief, Umberto Bossi. Salvini warned at the time that his party faced bankruptcy.

The Buzzfeed transcript of the Moscow meeting has an unidentified Italian saying money from any secret oil deal would be used to sustain a “political campaign” in an apparent reference to European parliamentary elections in May.

The League went on to triumph in the vote, doubling its score from national elections a year earlier to emerge as Italy‘s largest party for the first time in its history.