US Secretary of Commerce Gary Locke says he will address the arrest of Australian Rio Tinto executive Stern Hu, and three other employees, in his forthcoming meeting with Chinese Prime Minister Wen Jiabao. "This is of course a great concern with respect to US investors, multinational companies from around the world that have projects here, that are involved in energy," he said. Hu was arrested on July 5, suspected of commercial espionage, but has not yet been charged. Locke and US Energy Secretary Steven Chu are in China this week for meetings regarding the clean energy sector. "We need to have transparency, we need to have assurances and confidence that people working for these multinational companies, international companies, American companies will be treated fairly. So this needs to be raised with the Chinese," said Locke.