A group of Western insurers has said a Russian oil price cap has become unenforceable and only pushed more ships into joining a shadow fleet, delivering one of the harshest rebukes to the measure that had been meant to cut revenue to the Kremlin.

A group of Western insurers said the Russian oil price cap has become unworkable and has only encouraged more ships to join the shadow fleet, according to Reuters. The international P&I group said that the price cap has not had much success since its introduction two years ago,

A Group of Seven-imposed cap on the price of Russia oil is becoming increasingly unenforceable, an organization at the heart of the global insurance industry said, offering one of the most direct criticisms yet of measures that were meant to deprive the Kremlin of petrodollars.

The Russian economy ministry has downgraded its forecasts for the country's crude oil export prices for the next three years to $65 per barrel, according to an updated outlook seen by Reuters on Tuesday.