Bloomberg claimed at least four Taiwan-based companies are supporting a Huawei move to expand its domestic chip manufacturing capabilities, likely bypassing widening US trade sanctions by setting up undisclosed facilities.

The news outlet reported an investigation found employees from several Taiwan companies at a number of Huawei-affiliated facilities being built in Shenzhen, identifying staff from a unit of chip material reseller Topco Scientific and subsidiaries of L&K Engineering, along with construction specialist United Integrated Services.

Bloomberg wrote Cica-Huntek Chemical Technology Taiwan posted on its website it was awarded contracts to build chemical supply systems for local chipmakers Shenzhen Pensun Technology and Pengxinwei IC Manufacturing, which were added to a US list of excluded companies in 2022.

The pair are understood to work with Huawei on building its chipmaking capabilities.

Bloomberg noted it is unclear if the Taiwan companies’ work for Huawei violates the latest US sanctions, which restrict the export of chip technology to China rather than halting all joint business.

A Topco Scientific representative told Bloomberg a local subsidiary has an ongoing contract to handle waste water for Pengxinwei IC Manufacturing, which does not supply chip equipment or materials.

The source added the project is not prohibited by US sanctions and the contract was in place before the company was added to the list.

Bloomberg reported in August the US Semiconductor Industry Association (SIA) had claimed Huawei was secretly building chip manufacturing capabilities, with an estimated $30 billion in official funding.

Huawei’s latest Mate 60 Pro is thought by some to have 5G capabilities despite the chip restrictions, indicating gains in advanced chip manufacturing in the country.