Italian prosecutors opened an investigation into possible international corruption Thursday after the publication of a secret recording that suggests a close aide of Italy’s Deputy Prime Minister Matteo Salvini discussed illegally funneling Russian oil money to the far-right League party.

The secret recording, released by Buzzfeed, adds hard evidence to an account, published in a book earlier this year, of the meeting in October 2018 between Russian officials and Salvini’s longtime aide Gianluca Savoini.

The meeting, at Moscow’s salubrious five-star Metropol Hotel, saw Savoini discuss a deal: Russia would sell 3 million tonnes of diesel to an Italian oil company, from which money could be diverted to plug a hole in the League party's accounts.

The deal would covertly channel tens of millions of dollars of Russian oil money to the League party, the recording suggests.

On Thursday, Milan's Chief Prosecutor Francesco Greco said: “We are carrying out investigations to understand if there are crimes or not,” according to Italian news agency Ansa. Italian law prohibits political parties from accepting foreign funding.

While Salvini was in Moscow at the time the meeting took place, there is no evidence he was in attendance. There is also no evidence that the transaction took place.

But Savoini mentions his boss multiple times during the 75-minute meeting, describing him as “the first man that wants to change all of Europe” while the Russians describe Salvini as the “European Trump.”

During his meteoric rise to power, Salvini has made no secret of his affection for Russia, calling sanctions against Moscow “madness” and describing Vladimir Putin as “one of the best statesmen” in the world.

Last week, both Salvini and Savoini dined alongside Putin at a government banquet in Rome, and Putin told Italian newspaper Corriere della Sera that his United Russia party was working closely with Salvini's anti-immigrant League party.

Despite the fresh evidence to suggest illicit payments funneled from Moscow to the League’s coffers, it is unclear if the latest scandal will do much to significantly impact Salvini’s popularity, which helped him to a resounding victory in the European elections in May.

“The chance that this scandal may eat away at Salvini’s strength is extremely low,” Massimiliano Panarari, who teaches political communication at Luiss Guido Carli, a university in Rome, told the Washington Post.

When initial reports of the meeting appeared in February, both Salvini and Savoini dismissed them as a fantasy. Even after the recording emerged, Salvini has waved away the allegations, saying he has “never taken one ruble, one euro, one dollar or one liter of vodka in financing from Russia.”

On Friday, a Salvini spokesperson told Italian newspaper La Repubblica that Savoini has nothing to do with the League party, adding: “Savoini never was part of official delegations to Moscow with the minister.”

However, there is ample evidence to suggest otherwise.

This is far from the first time the Kremlin has been caught funding far-right European politicians.

Marine Le Pen, the leader of France’s National Assembly, took over $12 million in loans from Russian banks in 2014, while in Austria, far-Right FPO leader Heinz-Christian Strache was forced to step down in May after he was recorded offering government contracts in exchange for Russian campaign support.