I know this is from the daily mail.
There's been concerns over the use of Huawei equipment for years and possible backdoors. The following article perhaps gives more reliable and up to date info
https://uk.reuters.com/article/uk-huawei-security-britain-exclusive/exclusive-britain-says-huawei-shortcomings-expose-new-telecom-networks-risks-idUKKBN1K92BOReading between the lines it would appear HCSEC has found something they are not happy with "
they had identified technical issues which limited security researchers’ ability to check internal product code" which to me implies they found something that they can't check out because it's hidden/obfuscated/crypted. Whether what they found is bad or not, then no-one has any idea... which I guess leads to the question what is hidden and why.. which understandably leads to suspicion.
Huawei don't appear to be denying it and their response is "
The Oversight Board has identified some areas for improvement in our engineering processes.". A programme to resolve the code issue was underway and should be completed by mid-2020.