The husband of an Indian mother stabbed to death in a Sydney park remains a person of interest as police ramp up efforts to crack the near-decade-old murder.
Prabha Arun Kumar was found dead on a footpath in Parramatta Park, in Sydney's west, on March 7, 2015.
The 41-year-old was on the phone to her husband Arun in India when she was stabbed in the neck, with Mr Kumar reportedly hearing his wife confronted by her attacker.
But police on Monday said Mr Kumar remained a person of interest after multiple interviews, despite being overseas at the time of the killing.
The NSW government and police have announced a $1 million reward for anyone who could provide information that led to the arrest and conviction of Ms Kumar's killer.
Homicide Squad commander Danny Doherty confirmed the dead woman's husband had a girlfriend when the murder occurred, but he was not the only person being investigated.
"The appeal is as much about getting new information that may identify who was actually the person that stabbed Prabha, as it's documented her husband was in India at the time," he said.
"Let's be clear, we're keeping an open mind about what may have happened and we still have not got a confirmed person identified who's responsible."
The death is being treated as a targeted attack and police have dismissed any thought it was linked to robbery, sexual violence or racial bias.
NSW leaders were quick to quell community concerns after Ms Kumar's killing that the attack might have been because of her ethnicity.
Investigators previously flew to India and interviewed a number of individuals, including Mr Kumar.
The husband, who lived in Bangalore with the couple's daughter, flew to Australia when he learned of his wife's death.
She was said to be only weeks away from moving back to India because she missed her family.
"My wife was the most caring and beautiful soul," Mr Kumar said at the time.
Ms Kumar, who lived about 300m from where she was killed, moved to Australia in 2012 for a project with tech firm Mindtree.
The seven-figure reward would be available to anyone in India who could break the case open, Detective Superintendent Doherty said.
"Prabha was an Indian national … she was on a business visa in Australia, she was the bread-winner for the family ... there's people in India who may have information and may be able to assist," he said.
"The investigators haven't forgotten, the family certainly hasn't forgotten and the community needs to know we're working hard to resolve this murder."
A coronial inquest into Ms Kumar's death is set to take place in March.
Police Minister Yasmin Catley said police would not stop looking for answers until justice was served.
"Prabha's family deserve closure – someone out there knows something and there is now one million more reasons to get in contact with police," she said.
