The recent sharp increase in commodities prices has been powered by China increasing significantly its share of global raw materials demand, making prices vulnerable to a drop off in the country's strong buying, research by Barclays Capital shows.

The bank pointed out, for example, that Chinese share of global steel demand between January and April rose to 43 per cent, compared with 39 per cent a year ago, while its share of copper demand hit 38 per cent from 27 per cent over the same period of last year.

"China's import demand for a wide range of different commodities has soared. As a result, China's share of global commodities demand has accelerated markedly in the past few months," said Kevin Norrish, a commodities analyst at Barclays Capital in London.