For Austin Li's millions of fans, the evening of June 3 started like any of his other live stream sales events on Taobao, the biggest e-commerce platform in China.

On this particular night, he was selling an ice cream believed to be Viennetta, an iconic and beloved Australian sweet. 

As traffic peaked on the live stream, Li's staff member presented the ice cream adorned with what appeared to be five Oreo cookies, a Ferrero chocolate and a chocolate roll.

The cake was curiously shaped like an armoured tank. 

As Li's co-host took the plate from the staff, Li looked at the cake, smiling. 

All of a sudden, the stream was switched off.

As fans waited for it to be reconnected, Li posted an apology on Chinese social media Weibo, claiming the team was "having a technical issue."

He then made another post, announcing the termination of the live event. 

That was the last time Li's fans heard from him.

What Li and his fans didn't know at the time was that the sweet, creamy tank-like ice cream cake had triggered Beijing's special censorship system tailored for the 1989 Tiananmen Square anniversary on June 4.

China's Government is extremely sensitive to any allusion to the iconic image of a man standing in front of a column of tanks during the student-led protest movement. 

To this day, the photo — and anything referring to the massacre that followed — is banned in China.

Now all of Li's fans are waiting to see if he re-emerges later tonight. 

He is scheduled to appear in one of the three annual big e-commerce sales in China on June 18. 

But even though he is a lucrative salesman — once selling $2.2 billion in a single stream — experts say it's unlikely that Li will appear in public for a while.

A uni drop-out who defeated Jack Ma

Austin Li earned himself the nickname "the Lipstick King" after he broke live stream records by selling 15,000 lipsticks in five minutes. 

His sales prowess made him a big star for Taobao, an Amazon-like online shopping platform owned by Alibaba that allows people to buy everything from household gadgets to cosmetics. 

In 2018, Li went head-to-head with Jack Ma, who was the founder of Alibaba, in a lipstick-selling stunt. 

Li sold 1,000, while Ma only sold 10.

It seemed like a meteoric rise for the 30-year-old, who dropped out from university during his final year of dance studies. 

But the Lipstick King insists he did not achieve success overnight.

In an interview with Chinese media, Li said he started his career as a salesperson for cosmetic products.

He noticed many female customers were hesitant to try the lipstick testers at the counter, so he started to apply the products himself to model the colours. 

Li's unique approach made him the store's top salesman, and he soon gained attention from online influencer agencies.

In 2016, Li won a competition of beauty influencers, and he made his debut online.

China's influencers go live

Li made his debut the same year that Alibaba launched its live streaming platform, Taobao Live.

The service encourages shoppers to buy while watching influencers spruiking the products during live streams. 

Shoppers could also enjoy limited discount offers during the broadcast.

2016 was also the year that China's internet users dramatically expanded compared to the previous three years, with 43 million users online. 

The e-commerce live streaming platform has also become a lifesaver for China's private tutoring sector.

The government cracked down on the industry last year to ease financial pressure on parents.

But private English tutors now simply host their lessons via live streams. 

Dr Samuel Kwok, an associate professor in online luxury brand management at Xi'an Jiaotong-Liverpool University, said Li bridged the gap between e-commerce giants, brands and ordinary internet users.

He said Li's success was also the result of the growing power of young educated women who can afford entry-level luxury brands, and are willing to spend money on themselves.

"[Li] is very successful in targeting the mass [audience], particularly the ladies from late-20s to 40-something," said Professor Kwok.

Li was also aware of his fan base.

In each live stream, he would not only address his audiences as "sisters", but also tried the products himself. 

Li's skyrocketing popularity and his reputation as a hardworking businessman soon attracted attention from the ruling Chinese Communist Party.

Authorities, who denounced the growing trend of "lying flat" among young people amid intense work pressures last year, admired his work ethic. 

Last year, Shanghai's city government awarded Li a May 4th Medal, a party-backed honour for young people that acknowledges their "[contribution] to the development of the country".

Li also participated in Chinese state media-run propaganda shows, and was an ambassador for a social media campaign to promote the country's highest national prosecution agency.

But now, his bright future is on the brink — all because of an ice cream cake.

How a cake sent a red alert in China's complex censorship system

In the past five years, Li has rarely missed a daily live stream. 

While his name could still be searched on China's social media, the photo of him holding the tank-like cake has been censored on Weibo, China's largest social media platform.

Several hashtags related to Li were also limited during the week of June 4.

Eric Liu, a former social media censor for Weibo and now a free speech advocate in the US, said the censorship that Li experienced is a "normal reaction" from the platform over the 1989 Tiananmen protests.

"There is a very strict censorship system especially about Tiananmen protests," said Mr Liu.

"Firstly, if you post something that can be related to Tiananmen, such as a candle emoji between the night of June 3 and June 5, the post will be removed, and your account will be suspended." 

Some Chinese activists also try to use a random number combination that could indicate "8964" — the date of Tiananmen Square massacre, to avoid censorship.

But Mr Liu said even if the platforms fail to understand the meaning of such a post, they would still censor it and suspend the account to avoid any slips through the net.

According to Mr Liu, most platforms still rely on manual censors, supported by algorithms, to track down the sensitive words or images.

He said up to one month prior to June 4, censors would not be allowed to take any annual or sick leave, while their weekends would be shortened.

"This is to ensure they have enough staff to censor content relevant to June 4," he said, adding that censored content might be given to police as reference for arrest.

Why the Lipstick King may be replaced 

While Beijing has pushed platforms to undertake strict censorship to snuff out discussion of the Tiananmen protests, the censorship against Li has sparked waves of curiosity among young Chinese people, many of whom were born after the tragedy. 

On June 4, after Li's live stream sale was pulled, some users inquired about Tiananmen in his online discussion groups, with some mentioning they had used VPN to do the search.

Many of these posts were censored.

Mr Liu believed the Lipstick King was not aware that the tank-like cake could trigger the censorship about Tiananmen.

He said there have been similar incidents where businesses posted "what's the date today?" on June 4 and were immediately censored.

Dr Rose Lüqiu, an assistant journalism professor at Hong Kong Baptist University and a veteran journalist reporting on China, said it is unclear whether the censorship against Li was initiated by the platforms themselves or the government.

"[Li's disappearance] is the consequence of censorship, because nobody knows what's the red line, nobody wants to take the risk, especially for the platforms," she said. 

Professor Lüqiu said Li might still have hopes to make a comeback.

Unlike artists such as Hong Kong singer Denise Ho whose account was suspended on Weibo due to her pro-democracy political stance, Li's account was still there.

His previous content was still searchable on many platforms.

Even if Li overcomes this scandal, other challenges could lie ahead.

The massive profits of the live stream sale sector have recently caught Beijing's attention.

Last year, China issued a $21 million fine to Viya, the second most-popular live streamer after Li, over alleged tax evasion.

Li may also face potential backlash from his younger fans if he returns, said Professor Lüqiu.

"I think people in China, especially the younger generation, are used to the censorship system," she said.

"And they would find someone else to substitute [the person who disappeared]. New people would appear, and I think they would find their new interest."