Rio Tinto, the global mining company, boosted production of iron ore, its most valuable commodity, during the second quarter. The move reflects rising demand from China that underscores the group’s tense reliance on the country, even as Beijing launches an anti-corruption probe centred on Rio.

Rio’s iron ore division, its most revenue-generative last year, increased production to 45.1m tonnes, a 43 per cent rise compared with last quarter and an 8 per cent rise from the second quarter of 2008.