The head of MI6 Alex Younger has warned that Chinese phone giant Huawei could pose a threat to British security.

Younger said the UK will have to make a decision after allies, including the US, Australia, and New Zealand, barred Huawei from launching its 5G network.

Younger added that the arrival of 5G would make it harder for secret services to scrutinise Huawei's equipment.

The head of MI6 Alex Younger warned of a growing security threat from Chinese phone company Huawei at a speech on Monday.

In a rare speech at St Andrews University in Scotland, Younger said the UK will have to make "some decisions" about Huawei after allies, such as the US, Australia, and New Zealand, banned it from launching 5G networks.

"We need to decide the extent to which we are going to be comfortable with Chinese ownership of these technologies and these platforms in an environment where some of our allies have taken a very definite position," he said.

The US has led the charge against Huawei, whose founder was an officer in the People's Liberation Army, and the company is effectively locked out of the American market. However, that hasn't prevented Huawei from becoming the second most popular phone manufacturer in the world, behind Samsung.

Read more: The US is asking the world to say no to Chinese tech-giant Huawei

Younger said the arrival of 5G would make it more difficult to monitor Huawei's technology, some of which the UK already has installed in its telecoms network, and which is tested by British secret services at GCHQ.

He added that the Chinese government's approach to data protections means "they are able to use and manipulate data sets on a scale that we can only dream of."

You can watch Alex Younger's speech here: