Fighting talk, at last, from Rio Tinto. Sam Walsh, chief executive of the iron ore division, has described reports of bribery by employees as “wholly without foundation”. Almost a fortnight after its head of iron ore in China was detained, along with three colleagues, it was high time for a tougher line from the miner.

Kevin Rudd, Australian prime minister, had been landing all the punches; it is wise for him to take a step back, following Beijing's warning to Canberra to keep out of its affairs.

But Rio should have its dander up anyway. Its refusal to budge on annual contract negotiations with Cisa, the representative body for Chinese steel mills, has been vindicated by spot markets. The higher prices rise above the level agreed with Japanese, Korean and European customers – the margin is currently about 17 per cent – the more outlandish Cisa's claims for a deeper cut look.