Rio Tinto has signed a deal with the government of Madhya Pradesh in India that sees it commit to expanding its Bunder diamond project.
It has reached a state support agreement with the authorities and will now work towards advancing progress at the site, which is located 500km south-east of Delhi.
Research by the mining giant has indicated Bunder has an inferred resource of 27.4 million carats and managing director of the company's Indian operations Nik Senapti noted it has "significant" possibilities.
He described the arrangement as "a key milestone in our journey to unlock this potential by developing a world-class diamond mine".
The discovery was recently hailed as one of the largest diamond finds in the last decade by head of exploration for the business Eric Finlayson in an interview with Bloomberg.
He noted Rio Tinto is carrying out other exploration projects in the country, adding he is "pretty sure" they will be successful.