Chinese telecom giant Huawei has punished two employees for posting a New Year greeting on the company's official Twitter account using an iPhone made by arch rival Apple, an internal memo showed.

Huawei dislodged Apple last year from its position as the world's second biggest smartphone-seller, below global number one Samsung.

But in a public relations gaffe, the Chinese company wished followers a “Happy #2019” in a tweet on New Year's Day — marked sent “via Twitter for iPhone”.

Video producer Marques Brownlee shared a screenshot of the post with his three million Twitter followers before Huawei deleted it and sent another, this time marked “sent via Twitter Media Studio”.

One unnamed employee and Huawei's director of digital marketing were demoted and had their monthly salary slashed by 5,000 yuan ($730), according to the memo widely shared on China's Twitter-like platform Weibo and seen by AFP.

As well as the pay cut, the digital marketing director was also hit with a salary freeze and no promotions for the next 12 months.

Although the blunder was made by a third-party social media company called Sapient, the pair were disciplined for the “negative impact” on the Huawei brand caused by the incident, which highlighted ” procedural incompliance and management oversight”, the memo said.

In the memo dated Thursday, Huawei's corporate senior vice president Chen Lifang said the gaffe took place when Sapient used an iPhone with a Hong Kong SIM card to send the Twitter greeting after experiencing “VPN problems”.

Twitter — and other major foreign sites like Facebook and Google — are blocked in China and users need a virtual private network (VPN) connection to circumvent Beijing's internet controls.

Huawei did not reply to AFP's request for a comment on the incident.

The company has come under fire in 2018, with Washington leading efforts to blacklist Huawei internationally.

The arrest of its chief financial Officer Meng Wanzhou in Canada in early December — on a US extradition request linked to sanctions-breaking business dealings with Iran — has led to a surge of patriotism in China with companies encouraging staff to buy Huawei smartphones.

Several companies are offering employees subsidies for Huawei phone purchases, while others have even warned staff against buying Apple products, AFP found.

Huawei in December said it expects to see a 21 per cent rise in revenue for 2018 despite some of its telecommunications equipment being banned in several countries due to security concerns.