GCHQ not finding anything may or may not mean much, but recall that state-sponsored hackers in China are suspected in a number of really high tech computer intrusionsintrusions and espionage.
If we assume we could be moving to a Cold War 2, this puts China in a vastlyvery different light than Russia during Cold War 1 where no Western country would have bothered installing any critical Soviet civilian high tech infrastructure because that waswould have been an oxymoron.
Additionally, Huawei's CEO has somewhat close ties, supposedly, somewhat close ties with the Chinese military and CCP and that was another red flag in this context. Those accusations don't seem all that solid. And you'd expect many people joining the CCP to lubricate dealings with the government.
However, China does have a law compelling collaboration with the intelligence services.
Two pieces of legislation are of particular concern to governments — the 2017 National Intelligence Law and the 2014 Counter-Espionage Law. Article 7 of the first law states that “any organization or citizen shall support, assist and cooperate with the state intelligence work in accordance with the law,” adding that the the state “protects” any individual and organization that aids it.
And it appears that organizations and individuals don’t have a choice when it comes to helping the government. The 2014 Counter-Espionage law says that “when the state security organ investigates and understands the situation of espionage and collects relevant evidence, the relevant organizations and individuals shall provide it truthfully and may not refuse.”