It started with an image of U.S. Commerce Secretary Gina Raimondo on her China trip last month, reportedly taken on what the Chinese tech giant Huawei is touting as a breakthrough 5G mobile phone. Within days, fake ad campaigns on Chinese social media were depicting Raimondo as a Huawei brand ambassador promoting the phone.

The tongue-in-cheek doctored photos made such a splash that they appeared on the social media accounts of state media CCTV, giving them a degree of official approval.

VOA contacted the U.S. Department of Commerce for a reaction but didn’t receive a response by the time of publication.

Chinese nationalists spare no effort to tout the Huawei Mate 60 Pro — equipped with domestically made chips — as a breakthrough showing China’s 5G technological independence despite U.S. sanctions on exports of key components and technology. However, experts say the phone’s capability may be exaggerated.

A social media video posted by Chinese phone users shows that after the Huawei Mate 60 Pro is turned on and connected to the wireless network, it does not display the 4G or 5G signal indicator icon. But these reviewers say the download speed is on par with that of mainstream 5G phones.

A test done by Bloomberg also shows the phone’s bandwidth is similar to other 5G phones.

Richard Windsor, the founder and owner of the British research company Radio Free Mobile, told VOA a simple speed test is not good evidence that the phone is 5G capable.

“It is quite possible through a technique called carrier aggregation to get the kind of speed that was demonstrated,” Windsor said. “You can do that with 4G. … You will see the story on 5G is not [about] speed or throughput but latency efficiency and producing good reception at high frequencies. That’s what the 5G story is all about.”

Throughput and latency are ways to measure network performance. Latency refers to how quickly information moves across a network; throughput refers to the amount of information that moves in a certain time.

Huawei’s official website makes no mention of 5G technology, which also raised skepticism.

“If the new Huawei mobile phone was a 5G phone with an advanced Chinese chipset, Huawei and China would have told the whole world. Huawei and China are not humble people. They love to tell stories,” John Strand, CEO of Strand Consult, told VOA.

The research firm TechInsights took the Huawei phone apart and discovered a Kirin 9000 chip produced by Chinese chipmaker SMIC. The Kirin 9000-series chipsets support 5G connectivity.

While sanctions prevent SMIC from having access to the most cutting-edge extreme ultraviolet lithography tools used by other leading chipmakers — such as TSMC, Samsung and Intel — it could use some older equipment to make advanced chips.

However, experts suspect SMIC won’t be able to mass produce the Kirin 9000 chips on a profitable scale without more advanced tools.

“Being able to make a chip that works,” Windsor said, “and being able to make millions of chips at good yields that don’t bankrupt you in terms of costs are two very, very different things.”

VOA asked Huawei and SMIC for comment but didn’t receive a response by the time of publication.

Dan Hutcheson, vice chair of TechInsights, said in a press release that China’s production of the Kirin 9000 “shows the resilience of the country’s chip technological ability” while demonstrating the challenge faced by countries that seek to restrict China’s access to critical manufacturing technologies. “The result may likely be even greater restrictions than what exist today.”

U.S. national security adviser Jake Sullivan said during a White House press briefing Tuesday that the U.S. needs “more information about precisely its character and composition” to determine if parties bypassed American restrictions on semiconductor exports to create the new chip.

Rep. Michael McCaul, a Republican from the U.S. state of Texas, was quoted Wednesday saying he was concerned about the possibility of China trying to “get a monopoly” on the manufacture of less-advanced computer chips.

“We talk a lot about advanced semiconductor chips, but we also need to look at legacy,” he told Reuters, referring to older computer chip technology that does not fall under current export controls.