As the United States continues its campaign to urge allies not to use Huawei equipment for 5G networks, not everyone is convinced.

Germany’s top authority overseeing computer and communications security is pushing back on claims that the Chinese firm poses a security risk.

“For such serious decisions as a ban you need evidence,” said Arne Schönbohm, the president of the Federal Office for Information Security (BSI), according to an article on Friday in Der Spiegel.

Schönbohm noted that Huawei has gone above and beyond what other firms have done, opening a “security lab” in Bonn, the city where BSI is based. The facility allows customers to inspect Huawei products, including the source code of software.

When asked as early as in March of this year whether German authorities shared the concerns of US security agencies, Schönbohm said there are “currently no reliable findings” to support the claims.

Nonetheless, the momentum of the US campaign to keep Huawei equipment out of 5G networks of its allies has picked up steam in recent months, and private German firms may not be immune to the pressure.

Deutsche Telekom said on Thursday that it is “re-evaluating” its procurement strategy, citing concerns about Chinese-made gear.

“Nevertheless we are currently re-evaluating our procurement strategy,” the company was quoted as saying in an email to Bloomberg. “Deutsche Telekom takes the global discussion about the security of network elements from Chinese manufacturers very seriously.”

Australia and New Zealand announced policies over the summer which would effectively ban the use of Huawei for the next generation wireless operations. Japan unveiled last week policy changes that could prevent government procurement of equipment from Huawei and fellow Chinese telecoms giant ZTE.

The UK’s top wireless provider BT Group announced two weeks ago that they would strip Huawei equipment from existing networks and would not use the firm for 5G networks.