KIEV, July 25 ??“ Global Witness, a London-based non-government energy watchdog, called on the Ukrainian government to investigate the reasons for using RosUkrEnergo, a controversial Swiss-based gas trader, as the only gas supplier.

"Global Witness calls on the new Ukrainian government to organize a public investigation into RosUkrEnergo's access to the Ukrainian gas market, and whether such a company between Ukraine, Russia and Turkmenistan should exist,??? the organization said.