Chinese tech giant Huawei will be excluded from providing technology for the core 5G network being developed by U.K. telecoms firm BT.

The firm's equipment will also be removed from BT's existing 3G and 4G networks. While Huawei will not be selected as a vendor for the core 5G network, it will still be eligible to provide some infrastructure support – such as phone mast antennas.

BT acquired telecoms firm EE in 2016 and will use its existing network to launch a national 5G rollout. 5G will provide superfast mobile internet access and is widely expected to revolutionize technologies such as self-driving cars and the internet of things.

In an email sent to CNBC, a BT spokesperson confirmed the process to remove Huawei equipment from the core of its 3G and 4G networks began in 2016. They said this was done as a "part of network architecture principles in place since 2006."

"We're applying these same principles to our current RFP (Request for Proposal) for 5G core infrastructure," the spokesperson explained. "As a result, Huawei have not been included in vendor selection for our 5G core. Huawei remains an important equipment provider outside the core network, and a valued innovation partner."

EE is currently trialing 5G mobile internet in London's Canary Wharf.

A Huawei spokesperson told CNBC via email the firm would continue working with BT in the 5G era.

"We hope the U.K. will continue to provide Huawei with an equitable business environment," they said. "Cybersecurity should not be politicized, and equipment vendors should not be treated differently based on country of origin."