The New South Wales court of Criminal Appeal upheld Manisha Patel's appeal against the conviction and ordered a retrial, Sydney Morning Herald reported.
The then 32-year-old Manisha Patel was found guilty by a jury in July 2015 for allegedly killing 28-year-old Purvi Joshi in 2013 in Sydney.
She was sentenced to a maximum term of 24 years in jail, with a non-parole period of 18 years.
Purvi Joshi had arrived in Australia from India and was planning to marry Niraj Dave, a fellow Indian national who had previously been in a relationship with Manisha Patel.
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.