Con artists disguised as employees of a government-appointed agency have been duping restaurant owners into buying bogus energy-saving gadgets. The fraudsters claim the device, called 'star of environmental protection', can save the businesses money and protect the environment by cutting electricity consumption in half. Several restaurants had bought the fakes, police said, although they declined to give an exact number. The police have issued an urgent warning, fearing that other businesses such as lighting shops, pubs and commercial offices will be targeted. Fraudsters usually approach the restaurants in pairs, one posing as a salesperson, the other a technician, claiming to be from a government-appointed environmental protection agency. The price of the gadget was presented as discounted, with a six-month money back offer, police said. 'We believe fraudsters set a low price as bait to lure potential buyers and make them less suspicious,' a police officer said. In one case, a manager was told that a dim-sum restaurant needed three devices. Police said the gadget did not reduce electricity consumption and the government had never appointed any agency to tout, sell or install such devices. 'The public should be cautious and check the identity of any person who touts anything,' a police spokesman said. The Environmental Protection Department said it offered tips on how to save energy, but had never appointed any company to tout or install energy-saving devices. Chan Cheung-chor, chairman of the Estate Restaurants (Hong Kong) Merchants Association, said he was unaware of the scam. Mr Chan, who has been in the industry for 46 years, admitted that halving an electricity bill was an attractive offer - a dim-sum restaurant usually paid HK$100,000 to HK$200,000 for electricity a month.