The Hague/New Delhi, Nov. 10 -- The Netherlands has said it is "difficult" for anyone to track the origins of petroleum products, posing a question mark over the efficacy of European Union (EU) sanctions on Russian crude oil.

The Netherlands is the third-largest buyer of India's petroleum products, and its statement assumes significance given that it is the gateway for petro-product supplies to the EU through the port of Rotterdam, the largest European port. Meanwhile, India is the second-largest buyer of Russian crude exports after China.

It is difficult for any nation or organization to track the origins of oil products since they are mixed in "multiple places," Pieter ten Bruggencate, spokesperson for Netherlands climate and green gr...