As firecrackers thundered in the background in celebration, Ms Chou emerged from behind a blue cast-iron gate at the Guangzhou No.1 Detention Centre on Saturday morning – and was immediately swamped by family and friends – including her son Cleon, 19, a university student in Beijing, her sister Fiona Zou and 21-year-old daughter Chloe, who both flew in from Sydney.

Ms Chou will now wait for her travel documents to be processed before returning to Sydney, where she will be reunited with her youngest son Lincoln for the first time since she was first led away by police in mid-2008 – while the then one-year-old was asleep in their Guangzhou home.

As well as the personal toll, Ms Chou has lost the successful business she helped build, in a case mired in controversy involving feuding business partners and allegations of judicial bribery.  It is just one of a number of cases involving Chinese Australians embroiled in legal trouble in China that have highlighted the risks of doing business in China and prompted official representation from the highest levels of Australian government.

Travel entrepreneur Matthew Ng, who was sentenced to 11½ years in jail in Guangzhou for embezzlement, was last month transferred to a Sydney prison to serve out the remainder of his term.

Cardiac surgeon Du Zuying was detained in Shandong for more than three years before being released without charge in July. Both men had their businesses stripped off them by their former business partners.

Ms Chou was initially sentenced to 18 months' jail on bribery charges after Guangzhou police obtained a sleep-deprived confession during interrogation. Upon her release in December 2009, she was immediately re-arrested at the prison gate and charged with fresh counts of embezzlement.

"We were just standing outside waiting and chatting excitedly," her sister Fiona recalled. "Before we even were able to approach her two policemen came out of their waiting car and took her away."

Ms Chou's supporters say her former business partnerZhu Hanbang had bribed Guangzhou authorities to keep her in jail in order to wrest control of a profitable private university they had co-founded, the South China Institute of Software Engineering.

After unexplained delays and repeated court appearances Ms Chou was found guilty of embezzlement in 2012 and sentenced to eight years in jail, later reduced by three years after a re-trial.

The dropped charge revolved around a 29 million yuan ($5.3 million) amount prosecutors say was embezzled from the university, but which Ms Chou's lawyers long argued was a clearly documented loan. Prosecutors acknowledged for the first time during the re-trial last October that the loan did in fact exist. Bank records and shareholder documents proving existence of the loan had previously not been considered by the court.

After returning to Sydney, Ms Chou will likely continue to the fight to retain control of her business through a string of concurrent legal cases, her sister said, but would first make up for lost time by spending time with family and friends.

But she said first on the agenda for Ms Chou - who asked for a beanie to be delivered for her to wear upon her release - would be a trip to the hairdressers to dye her hair, which had gone almost completely grey during her time behind bars.