Russia's second-richest man, hit by British sanctions on Wednesday, had his superyacht berthed in Dubai, one of three ultra-expensive, oligarch-owned boats moored in the Gulf financial hub.

Vladimir Potanin, whose fortune Forbes magazine estimated in 2021 at $27 billion, had his assets frozen and was handed a travel ban and other restrictions, the British foreign ministry said.

His 88.5-metre (290 feet) yacht Nirvana -- complete with jacuzzi, a swimming pool that converts into a dancefloor, and a 3D cinema, according to a chartering website -- was once listed at $300 million, reports said.

Dubai, long known to Russians as a high-end holiday destination, has been a magnet for the country's professionals and elite fleeing the impact of Western sanctions since the invasion of Ukraine. 

Berthed close to Nirvana at Dubai's Port Rashid on Wednesday was Madame Gu -- a 99-metre superyacht reportedly owned by Russian billionaire Andrei Skoch, sanctioned by the European Union and Britain.

Quantum Blue, another luxury vessel which reportedly belongs to Russian retail tycoon Sergey Galitsky and has an elevator, beauty salon and helipad, according to yachtcharterfleet.com, was also docked at Dubai port.

Some yachts linked to sanctioned Russians have been seized. This month, a Fiji court handed the $300 million Amadea to US authorities, and other floating palaces have been impounded in Spain, Italy and France.

Last week, US deputy treasury secretary Wally Adeyemo visited Dubai, calling for "vigilance" against attempts to evade sanctions against the Russian financial system, the Financial Times said.

The United Arab Emirates has announced a drive against money-laundering after being placed on the grey list of countries subject to heightened scrutiny by the Paris-based Financial Action Task Force.

"The UAE takes its role in protecting the integrity of the global financial system extremely seriously," a UAE government official told AFP.

"We work closely with the private sector to implement targeted financial sanctions and combat sanctions evasion in line with international obligations and practices, and the UAE remains steadfast in this commitment without exception."