An Indian cement maker's recent purchase of Russian coal using yuan involved India's biggest private lender, HDFC Bank, according to an invoice seen by Reuters and a source, as more details emerge of the kind of trade that could blunt Western sanctions against Moscow.

There is no suggestion that the purchase, the particulars of which have not previously been reported, in any way breaches sanctions imposed on Russia in the wake of its invasion of Ukraine.

But the document shows one way in which Russia could continue to sell commodities abroad without settling in U.S. dollars despite restrictions aimed at freezing it out of financial markets.