The US has issued an indictment that accuses Huawei of stealing trade secrets and then lying to US investigators when questioned.

Reported in the Guardian, Huawei is said to have “successfully engaged in a decades-long effort to steal intellectual property, giving it an unfair advantage over competitors.” The indictment also accuses Huawei of supplying its goods to Iran and North Korea in violation of US, European and UN sanctions.

Among the allegations are of Huawei lying about its involvement with Skycom (first reported by Reuters), a company said to be a covert Huawei subsidiary that allowed Huawei to assist Iran in questionable domestic surveillance methods.

The allegations come days after the US also claimed Huawei already has the ability to spy on global mobile telecoms networks in which its hardware is installed. The two reports combined are sure to heighten further the tensions created by the UK government and the US after the former decided to use Huawei equipment in its new 5G networking plans.

The US placed a trade ban on Huawei last year after it charged the company’s founder’s daughter and CFO Meng Wanzhou with fraud. While the ban has been damaging to Huawei’s handset business in the west, the UK’s acceptance of its 5G networking equipment has riled the US, who is now beginning to show more evidence of Huawei’s alleged fraud in an attempt to dissuade other countries from following the UK’s lead.

Huawei equipment is said to create back doors to the Chinese government for illegal surveillance of foreign citizens and their data, but the US has never provided any public evidence. Huawei’s 5G equipment is cheaper than the alternatives offered from Ericsson and Nokia.