The US government has broadened its legal case against Huawei, combining individual charges of fraud, intellectual property theft and obstruction of justice into accusations of a sprawling 20-year criminal conspiracy. The Department of Justice said on Thursday that it had charged Huawei with racketeering, a charge most famously used to dismantle American Mafia families, which allows leaders of an organised crime syndicate to be tried for crimes they ordered others to do. Officials also charged the Chinese telecommunications giant with a years-long conspiracy to plunder trade secrets from five more US companies, having already accused it last January of stealing plans for a smartphone-testing robot from the US phone company T-Mobile. The racketeering charge wraps in existing allegations that Huawei broke US sanctions against Iran by operating a secret subsidiary there, and further claims that Huawei did similar work in North Korea stretching back to 2008. The Department of Justice said: "Huawei’s efforts to steal trade secrets and other sophisticated US technology were successful. Through the methods of deception described, the defendants obtained non-public intellectual property relating to internet router source code, cellular antenna technology and robotics. "As a consequence of its campaign to steal this technology and intellectual property, Huawei was able to drastically cut its research and development costs and associated delays, giving the company a significant and unfair competitive advantage." It added that Huawei had allegedly lied to FBI agents and to members of the US Congress, as well as obstructing the Department"s investigation. A spokesman for Huawei said: "We are private employee-owned company that respects the law in every one of the 170 markets where we operate." The company pleaded not guilty to the previous indictment last January, which charged it with defrauding banks through its alleged operations in Iran. The new indictment includes vivid details of alleged technology theft, including an engineer who was "discovered in the middle of the night" at a trade show in Chicago with a badge listing his employee as "Weihua". It accuses Huawei of operating a monthly bonus scheme for acts of espionage, with a special team employed to judge which employees had "provided the most valuable stolen information". It also personally named Huawei"s chief financial officer, Meng Wanzhou, who is also the daughter of its founder Ren Zhengfei and who is currently undergoing extradition hearings in Vancouver, Canada.