The hardline minister, who is known for regularly praising Russia and its president Vladimir Putin, threatened to sue over the allegations on Wednesday.
“I have sued in the past, I will do it again today, tomorrow and the day after tomorrow,” Salvini said in a statement following the release by news website BuzzFeed of what it said was a transcript of covert talks in Russia.
“Never taken one ruble, euro, dollar or litre of vodka in financing from Russia,” said Salvini, whose party forms half of Italy's ruling coalition government.
BuzzFeed identified the aide as Gianluca Savoini and said the October 18 meeting was the latest evidence of collusion between Moscow and far-right European populist movements.
We have obtained a secret audio recording of a Moscow meeting between three Russian operatives and a close aide to Italian Deputy Prime Minister Matteo Salvini negotiating a plan to pump money from a Russian oil deal into Salvini’s far-right Lega partyhttps://t.co/Qdwx8rO7BD
— Alberto Nardelli (@AlbertoNardelli) July 10, 2019
According to the transcript, the talks at a hotel in Moscow centred on a possible deal involving a Russian oil company selling around three million metric tons of fuel to Italian oil giant Eni over a year, with a value of around $1.5 billion.
The six men present – Savoini and two other Italians, plus three unidentified Russians – discussed funnelling money from the deal into the League's coffers, BuzzFeed said.
“Their nominal purpose was an oil deal; their real goal was to undermine liberal democracies and shape a new, nationalist Europe aligned with Moscow,” it said.
The news site said it was “unclear whether the agreement negotiated at the Metropol hotel was ever executed, or if (Salvini's) Lega received any funding”.
Savoini told AGI news agency “the League never took a cent from Russia.”
“Only one thing counts: the truth. The rest is just talk,” he said.
Opposition parties in Italy have called for an immediate investigation.
The League has been developing ties with Russia since 2013, and in 2017 it signed a cooperation deal with the ruling United Russia party.
Salvini has travelled to Russia on multiple occasions and regularly shares pro-Russia posts on his social media accounts.
He has repeatedly rejected allegations of Russian meddling in Western democratic processes, including in the last Italian election.
Since coming to power, the current Italian government has repeatedly called to de-escalate tensions with Russia and end all EU sanctions against Moscow put in place since the 2014 Ukraine crisis.