In what the French press is calling “Monaco-gate,” Philippe Narmino, the minister of justice for Monaco, has resigned after French newspaper Le Monde published text messages revealing that he worked on behalf of Russian oligarch Dmitry Rybolovlev to influence a billion-dollar art fraud case.

Narmino, 64, reportedly decided to take “early retirement” just hours after Le Monde posted the texts, which suggest “a vast influence-peddling scandal at the heart of Monaco institutions,” according to the newspaper. artnet News reached out to Monaco’s Ministry of Justice, which referred us to the Monaco Court of Justice. The court had not responded to request for comment as of publication time.

Rybolovlev, 50, is a mining billionaire and a majority owner of AS Monaco football club. He allegedly recruited Narmino and other officials in the Ministry of Justice to help him pursue Yves Bouvier, a prominent Swiss art collector and dealer who once represented the billionaire. Rybolovlev claimed that Bouvier cheated him out of as much as $1 billion by misrepresenting sale prices on some 38 artworks, including pricey masterpieces by Leonardo da Vinci, Pablo Picasso, Amedeo Modigliani, and Van Gogh—which the billionaire bought for a total of $2 billion.

According to reports, hundreds of text messages exchanged between Rybolovlev, his attorney and close associate Tetiana Bersheda, and Narmino included information about an all-expenses-paid ski trip for Narmino and his wife at the billionaire’s Swiss chalet in Gstaad, as well as a private helicopter ride and other expensive gifts.

The messages also reportedly suggest Bersheda was in close contact with the Monaco police about a plan to arrest Bouvier after “luring” him to Monaco. The dealer was arrested there in early 2015 following the allegations by Rybolovlev and then released on €10 million bail. Several high-ranking Monaco police officers—including former police chief Regis Asso—are also reportedly involved.

Ron Soffer, an attorney for Bouvier based in France, says the charges against his client are bogus. “Mr. Bouvier strongly believes in his innocence and that he will not be charged with any crime,” the lawyer told artnet News. “He continues to have confidence in the impartiality of the Monaco judiciary and the investigating magistrate leading the investigation.”

Francis Szpiner, another Paris lawyer working for Bouvier, told Le Monde that he had long suspected that Rybolovlev’s connections and influence with local officials played a role in the Bouvier dealings. He claims there is now evidence that the police, the prosecutor’s office, and the minister had done everything possible to carry out the scheme. Szpiner said he wanted to call on Prince Albert to investigate these officials.

A spokesman for Rybolovlev had not responded to artnet News’ request for comment as of publication time.