The Indian refineries have settled the first installment of $550m on 26 June whereas the second was paid on 8 July, under an interim deal that enabled Iran access to $4.2bn in blocked funds globally, according to Press Trust of India.

India will pay its final installment of $550m for crude-oil imports to Iran by the end of July 2014, if Iran meets all of its commitments under the joint action plan.

Wall Street Journal cited one of undisclosed person as saying, "Indian refiners have paid two installments of $550 million each. A third installment of an equal amount will be paid later this month."

Since the US sanctions blocked payments to Iran from February 2013, India has been paying 45% of its oil dues in rupees through state-owned UCO Bank to Iran.