BHP Billiton Ltd, the world's biggest mining company, lobbied Australia last year to stop Aluminum Corp of China's proposed $19.5-billion investment in Rio Tinto Group, the Sydney Morning Herald reported, citing a former government official.

BHP executives, including Chairman Don Argus, met officials including Prime Minister Kevin Rudd and Treasurer Wayne Swan to discuss the proposed investment, the newspaper said. E-mails from BHP were circulated throughout the government, the Herald cited former Treasury official Stephen Joske as saying.

Rio Tinto rejected Chinalco's proposed deal in June in favor of a share sale and an iron ore joint venture with BHP.