A Sardinian nightclub frequented by Silvio Berlusconi and famous for its high-spending customers has called in the police after a group of Russians racked up an €86,000 (£75,000) champagne bill before vanishing. The eight young Russians ordered 90 bottles of champagne as well as bottles of spirits during a long night at the Billionaire nightclub, where guests from yachts anchored off the Emerald Coast pay €900 for a bottle of Cristal.

"Their reservation was made through their charter yacht, which also guaranteed payment of the bill," said the club's spokeswoman, Patrizia Spinelli. "The club was full of big spenders and the Russians seemed no different." Witnesses said the would-be oligarchs were spraying each other with champagne at the club. Billionaire, which is part-owned by the motor-racing tycoon Flavio Briatore, is close to Villa Certosa, Berlusconi's summer retreat, and has hosted Lele Mora, the celebrity agent under investigation for allegedly supplying the Italian prime minister with prostitutes.

Free-spending Russian oligarchs are also a common sight at Billionaire during the summer months. "Many customers reserve through their yachts, middle men or PR firms and we don't know who they are," said Spinelli, who added that it was normal practice for bills to be taken care of the day after, if guarantees had been given.

"The following morning, August 5, we contacted the yacht to settle the bill, only to be told that no payment would be made, possibly because the Russians had said they would not pay up," she said.

Staff at the club reported the charter boat's captain to the local paramilitary police who located the vessel, named by Italian media as the Kismet. "The Russians were gone by the time we got there, probably on their way back to Russia," said Giulio Brandanu, an investigating officer. A local magistrate is now pursuing the case.

"We have seen people here skip out on drinks bills before, but never this much," said Brandanu.

Spinelli said Billionaire had sought to keep the case under wraps, but details had been leaked to a local paper. "This episode is an incredible exception in a world of gentleman customers," she said.