Britain's largest mobile provider revealed on Wednesday it was removing the equipment of China's telecoms giant Huawei from its 4G cellular network.
BT's announcement comes with Washington reportedly pushing its allies to shun Huawei technology as they roll out next-generation 5G networks.
The move also comes after the head of MI6 foreign intelligence service this week singled out the Chinese company as a potential security risk.
Huawei -- one of the world's largest mobile equipment and service providers -- has long been under scrutiny over its allegedly close ties to China's state intelligence services.
Both Beijing and the company deny the charge.
BT said it has been in the process of removing Huawei equipment from instrumental parts of its 3G and 4G mobile networks since 2016.
It said in a statement that the decision was made "as 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 British group added.
"As a result, Huawei have not been included in vendor selection for our 5G core."