The UK's National Crime Agency (NCA) on Wednesday issued a red alert to the financial sector warning that Russia was using gold to evade sanctions imposed after it invaded Ukraine.

The NCA said deliberate attempts were being made "to launder sanctioned gold to mask its origin so that it can be hidden in supply chains and sold in the UK and around the world".

Gold exported from Russia since July 2022 is "increasingly being shipped to countries that do not apply sanctions on Russian gold," said the agency, which tackles serious, organised and international crime.

It can then be melted down and recast or refined, hiding its origins.

As a result, the UK said on Wednesday that it had placed 29 new sanctions on "individuals and entities operating in and supporting Russia's gold, oil and strategic sectors".

Those targeted include a United Arab Emirates-based network that the Foreign Commonwealth and Development Office says is responsible for channelling more than $300 million in gold revenues to Russia. 

The UK has also sanctioned two of Russia's largest gold producers, Nord Gold PLC and Highland Gold Mining Limited, along with Russian oligarchs Vladislav Sviblov and Konstantin Strukov.  

Gold is a one of the largest income streams for Russia's war effort after oil and gas, and was worth £12.6 billion to the Russian economy in 2021. 

"This alert will aid efforts, in partnership with the regulated sector, including the banks and high value dealers, to ensure that sanctioned individuals or those who represent them cannot use gold to circumvent UK sanctions," said Adrian Searle, director of the National Economic Crime Centre at the NCA.

The London Bullion Market Association accredits gold refineries around the world and sets the standards for what constitutes "London Good Delivery" gold - the de facto global standard. 

LBMA accredited refineries account for up to 92 percent of annual global mined gold production.