Executives from all 16 Chinese steel mills participating in iron ore price talks this year have been bribed by Rio Tinto employees, an industry insider claimed yesterday, amid reports that the government is considering invalidating 20 iron ore import licenses to regulate the chaotic ore import business.

The startling claim comes amid a widening probe of alleged business espionage linked to the world's second-largest iron ore miner, Rio Tinto.

Executives from five leading domestic steel makers and officials from the industry association are reportedly under investigation following last week's detention of four employees of Rio Tinto's China operation, including an Australian.