Mysterious buyers with suspected links to Russia have begun amassing dozens of vessels capable of carrying liquefied natural gas, in moves that suggest Moscow is expanding its “dark fleet” of energy tankers.

Shipping industry insiders say a clutch of previously unknown companies, largely registered in the United Arab Emirates, have rapidly acquired LNG vessels over the past year, driving up market prices, especially for the oldest ships.

The buying spree has echoes of how Moscow established a dark fleet of tankers to shuttle oil around the globe in the face of western sanctions, often using the UAE as a centre for energy trades. Although Russian LNG sales are less affected by western sanctions than oil, Moscow has been preparing for restrictions to tighten.