An aide to Italy’s deputy prime minister Matteo Salvini, at the center of accusations the ruling League party sought millions of euros via a secret Russian oil deal, flew back-and-forth to Moscow last year, news website BuzzFeed said on Thursday.

Flight records show Salvini’s former spokesman Gianluca Savoini went to Moscow on three separate occasions last year in the run-up to an October meeting where the proposed covert oil deal was discussed, BuzzFeed reported.

In the weeks after, he made a further three, unexplained trips to Russia, the report added, citing a joint investigation with two other websites Bellingcat and The Insider.

The report may put further pressure on the League’s leader Salvini as its ruling coalition, with the anti-establishment 5-Star Movement, appears close to collapse.

Both Salvini and Savoini have denied the League received any money from Moscow. Party officials were not immediately available to comment on the BuzzFeed article.

Italian prosecutors last month opened an investigation into possible international corruption following reports the League had been involved in a secret deal.