View of a Huawei advert outside an Apple Store in Shanghai, China. Feature China | Barcroft Images | Barcroft Media via Getty Images

China's Huawei Technologies has punished two employees for New Year greetings sent on the smartphone maker's official Twitter account using an iPhone, an internal memo showed. Huawei, whose P-series handsets compete with Apple's iPhone, on New Year's Day wished followers a "Happy #2019" in a tweet marked sent "via Twitter for iPhone." The tweet was quickly removed but screenshots of the blunder spread across social media. "The traitor has revealed himself," quipped one user on microblog Weibo, in a comment 'liked' over 600 times.

In an internal Huawei memo dated Jan. 3 seen by Reuters, corporate senior vice-president and director of the board Chen Lifang said, "the incident caused damage to the Huawei brand." The mistake occurred when outsourced social media handler Sapient experienced "VPN problems" with a desktop computer so used an iPhone with a roaming SIM card in order to send the message on time at midnight, Huawei said in the memo.

Twitter, like several foreign services such as those from Facebook and Alphabet, is blocked in China, where the Internet is heavily censored. To gain access, users need a virtual private network (VPN) connection. Huawei, which overtook Apple as the world's second-largest smartphone vendor by volume in January-September, declined to comment on internal issues when contacted by Reuters. Sapient did not immediately respond to a request for comment sent via the contact form on its website. Calls to its Beijing office went unanswered. WATCH: The United States thinks Huawei is a security threat