What would prompt more than 1000 people to sign an online petition in support of a University of Sydney tutor who calls his mainland Chinese students 'pigs'? The answer, in part, is another reflection of the widening schism within Australia's evolving Chinese community.

Wei Wu, a 26-year-old tutor at the university's business school, resigned on Monday after a group of students collated derogatory remarks he made on Chinese social media site Weibo stretching back more than a year ago. It prompted an official university investigation, and reports of the news went viral in mainland China.

Among Mr Wu's incendiary actions online included posting a video of himself burning his Chinese passport (after he obtained Australian citizenship), extinguishing the flames in a toilet bowl. He berated the intelligence of some of his mainland Chinese student cohort, and referred to them as liuxuetun (留学豚), which can be transliterated as "international student pigs".

The advent of social media, in particular chatting app WeChat – ubiquitous across mainland China – has made it easier for international students to band together to share information and study tips, while overcoming isolation and the inevitable language and cultural barriers that come with studying in a foreign land.

On this occasion, the 500-strong WeChat group of Sydney University business school students was furiously discussing the tutor's Weibo posts, and how to retaliate. "In China, he would have been made into [pig] feed long ago," one comment read. "I'm going to explode," read another.

Fanning the flames further was an online WeChat news account by the name of "Australian Red Scarf", a clear patriotic reference to the neckerchiefs worn by Young Pioneers. Its report, which pre-dated the eventual petition, combed through Mr Wu's social media history, dug up his photos, and disseminated his email address and LinkedIn page. In Chinese netspeak, this is known, rather insidiously, as a "human flesh search".

At the receiving end of some exhaustive trolling and numerous threats of violence, Mr Wu deactivated his Weibo account and has set his Twitter account to private. His WeChat account is also unresponsive, according to friends.

Mr Wu uses the character tun (豚), which also means pig in Japanese but is archaic in Chinese, where the vastly more common used character is zhu (猪). In online dissident circles, the character tun has been co-opted as a form of political slang with its roots likely from the derogatory Japanese term zhinatun (支那豚).

The term haitun (海豚), which literally means dolphin, has been co-opted in those circles to mean overseas Chinese who are prone to believe party propaganda and are therefore nationalistic. It an extension of the more commonly seen wordplay around haigui (海龟) which literally means sea turtle but in online slang also refers to Chinese who studied overseas but have since returned home. And haidai (海带) means both seaweed, and Chinese students who return from overseas but are waiting to find work.

"It [tun] is actually a euphemism used online to refer to guanerdai, the second-generation [offspring] of [Communist Party] officials who have gone overseas to study," Wai Ling Yeung, the recently retired head of Chinese Studies at Curtin University, said.

"One of the characteristics of these overseas students from very rich families is that their families very closely connected with the party, they are very supportive of the party."

The relative obscurity and subversiveness of the term meant many mainland Chinese would not be aware of the political subtext, added Dr Yeung, who is also an accredited translator.

Tony Pun, of the Chinese Community Council of Australia, had initially called for the case to be referred to the state's anti-discrimination board. But he now said "we do not believe he was racist".

"Young people do make mistakes, in this case, despite his high intelligence, he was not wise."

Mr Wu has declined to speak to media. While he is not known to be active in Chinese-Australian dissident circles, they have been quick to embrace him as a cause celebre, criticising Sydney University for "pressuring" him to resign in order to placate their most lucrative international student base. Mr Wu's supporters insist he has been persecuted for his political views and criticism of the Communist Party. The burning of his passport, more than anything, generated the bulk of the backlash, they say.

Prominent Adelaide-based dissident artist Badiucao has lent a series of artworks to support the pro-Wu counter-petition, including one where the sandstone buildings of Sydney University are re-imagined as Tiananmen Square, replete with a portrait of Chairman Mao.

"Political dissent is NOT racism," reads one supporter's comment on the counter-petition.

Quite apart from whether it is possible for an ethnic Chinese person to be "racist" toward another, Mr Wu's missives on social media – and the huge attention it garnered – provides a strong argument his position was untenable.

And while some will form the view that dissident voices will sign anything that criticises China, many of the comments left on the counter-petition expressed calm concern that the attack on Mr Wu was the latest sign of creeping influence of pro-Communist Party forces operating in academia and in Australian society more broadly.

A gathering of 60 leaders of Chinese patriotic associations in Sydney warning Prime Minister Malcolm Turnbull to watch his words when discussing China's South China Sea territorial claims, reported by both the ABC and Fairfax Media, prompted more than 3000 comments on a popular online Chinese-Australian community forum.

The fierce debate was largely divided among two camps: naturalised Australians from families who migrated in the 1980s and 1990s with the spectre of the Tiananmen Square crackdown of 1989 fresh in their memories, and more recent émigrés who have been enriched by China's economic miracle of the past two decades.

The demographic is shifting toward the second camp as more mainland Chinese arrive on business, investment and student visas, all the while President Xi Jinping's administration becomes more proactive in cultivating overseas Chinese, including through United Front organisations, to support the Communist Party's soft power objectives.

"We are concerned that Mr Wu is becoming a victim of the Chinese government's increasingly intrusive attempts to curb voices of dissent among overseas Chinese," the counter-petition reads.