Her husband heard it from 10,000 kilometres away, but it seems no-one saw the stabbing murder of 41-year-old software engineer Prabha Arun Kumar in a Westmead park in March. Except the person who stabbed her.

Ms Kumar was on her way home from work, talking on her phone to her husband in India when she was attacked on a public walkway through Parramatta Park near Amos Street on March 7.

Now police want to speak to a person who can be seen in new CCTV footage walking nearby through Parramatta Golf Course near Jubilee Lane on the night of her murder.

"The person in the footage is the one person we have not been able to identify so far," after months of exhaustive inquiry, said Detective Acting Inspector Ritchie Sim.

The footage showing a figure in the shadows came to light during recent canvassing of the area.

The search will now be widened to India with detectives from Strike Force Marcoala, formed by the State Crime Command's Homicide Squad to investigate Mrs Kumar's death, due to travel to her home town.

"Considering the nature of the investigation and because it is Prabha's home town, it is an obvious line of inquiry. It's important we don't speculate but we need to exhaust every line of inquiry" Detective Sim said.

Earlier footage showed Mrs Kumar walking alone on a well-lit concourse near Parramatta station just minutes before she was attacked when she took a short-cut through the park. She had just finished a double shift as an IT worker.

Mrs Kumar's brother-in-law Thrijesh Jayachandra told The Hindu Mrs Kumar's husband heard his wife pleading with her attacker.

"He heard her scream for help and then plead with the man not to harm her and take all her belongings if he wanted. Seconds later he heard her scream and say she was stabbed."

Mrs Kumar was stabbed several times in the neck. She collapsed on the walkway and was found by a passer-by in a pool of blood. Police arrived at the scene about 9.30pm and Mrs Kumar died later that night in hospital.