One cyber security expert, with connections to the federal government, said the concern around WeChat was not only its close association with the Chinese state, but how a user's data could potentially be exploited.

"The understanding is that applications like WeChat have a higher ability to aggregate and monitor data," said the person, who asked not to be named.

"They [Defence] would be very nervous about software being loaded onto a device which could then access a secure military network."

The Indian Defence Ministry moved to ban WeChat and other Chinese apps in December over fears they could contain spy or malicious ware.

"Use of these apps by our force personnel can be detrimental to data security having implications on the force and national security," the Ministry said in a memo obtained by the Indian Express newspaper.

Despite such concerns from the defence establishment business remains open to its staff using WeChat. Two professional services firms told the Financial Review their staff often used WeChat when dealing with Chinese clients.

This is despite well-documented concerns around data security from the likes of Amnesty International.

In an October 2016 report, Amnesty looked at the effectiveness of the encryption systems used by 11 global technology players and in doing so ranked WeChat last.


It scored WeChat zero out of 100, while Facebook messenger and WhatsApp scored 73 out of 100.

The concerns around WeChat are part of a growing national security backlash against Chinese foreign investment in everything from critical infrastructure, to mobile phone handsets made by mainland firms Huawei and ZTE.

After allowing Huawei phones to be used by Defence personnel, despite the company being banned from the National Broadband Network (NBN), Fairfax Media reported last month the Department was phasing out the devices.

This follow a blunt warning from the director of the US National Security Agency (NSA), Mike Rogers, who said politicians and officials should "look warily" on products from Huawei and ZTE.

"I would say you need to look long and hard at companies like this," he said.

At the same time US officials are warning about any Huawei involvement in Australia's soon to be built 5G mobile phone network.

The Financial Review has reported Prime Minister Malcolm Turnbull was briefed by intelligence agencies on US concerns about Huawei's involvement in Australian 5G networks during his recent visit to Washington.

This has set the scene for a major diplomatic showdown between Canberra and Beijing, at a time when relations are already strained.

The federal government will empower itself to intervene in the 5G roll-out through new legislation, which has been dubbed the "anti-Huawei bill".

The Department for Home Affairs has said the telecommunications sector security reforms (TSSR), which come into effect in September, will allow the government "to provide risk advice to mobile network operators or the relevant minister to issue a direction".