BBC Newsnight is in international waters off the coast of Greece to see how Russian oil continues to be exported around the world.
We see evidence that millions of barrels of Russian oil is still going into the production of energy burned by countries imposing the sanctions.
For the first time we have a sense of the value to Russia of energy burned by the UK.
The figures were calculated by the environmental campaign group Global Witness and reviewed by BBC Verify and independent experts.
The story is reported by Newsnight’s International Correspondent Emir Nader.
Ayman Oghanna was the producer and director.
Please subscribe here: http://bit.ly/1rbfUog