An investigation of Huawei Technologies Co.’s latest AI offering has unearthed an advanced processor made by Nvidia Corp. manufacturing partner Taiwan Semiconductor Manufacturing Co., suggesting that China is still struggling to reliably make its own advanced chips in sufficient quantities.

Canada-based research firm TechInsights recently took apart at least one of the Shenzhen conglomerate’s highest-end artificial intelligence accelerators and discovered an Ascend 910B chip manufactured by TSMC, according to people familiar with a recent teardown of the devices. They requested anonymity to discuss a report that isn’t public.

Huawei has been on a US sanctions list since August 2020, meaning the company is barred from doing business with TSMC and its contract chipmaking peers without a US government license. In the past year, Huawei has relied on local partner Semiconductor Manufacturing International Corp. for production, including a 7-nanometer chip debuted last August in a Huawei smartphone.

US officials have repeatedly cast doubt on SMIC’s ability to make 7-nm chips at scale and questioned the performance of those components. Huawei’s use of TSMC output for its latest AI chips may be a sign that reinforces that narrative. It remains unclear how and when Huawei obtained the TSMC chips. The Taiwanese chipmaker has said it stopped all shipments to Huawei after Sept. 15, 2020, which the company reiterated when asked about the TechInsights report.

“TSMC is a law-abiding company, and we are committed to complying with all applicable rules and regulations, including applicable export controls. In compliance with the regulatory requirements, TSMC has not supplied to Huawei since mid-September 2020,” the company said in an emailed statement. “We proactively communicated with the US Commerce Department regarding the matter in the report. We are not aware of TSMC being the subject of any investigation at this time.”

In its own statement, Huawei said it hasn’t “produced any chips via TSMC after the implementation of the amendments made by the US Department of Commerce to its FDPR that target Huawei in 2020,” a reference to the foreign direct product rule — a US trade restriction. “Huawei has never launched the 910B chip,” the company said.