The image of the man, described as being of Mediterranean/Middle Eastern appearance was released on Monday, almost four months after the 85-year-old was abducted from his home in Sydney's north in the early hours of February 13.
Four men have already been charged and remain before the courts.
On Monday, police called on anyone with information about the man, seen in a hardware store in Leppington at 7.39am on Wednesday, Â February 11, to contact Crime Stoppers.
The widower was not the intended target and had been taken in a case of mistaken identity, police have said.
They made several public appeals, urging the kidnappers to release the 85-year-old and return him to his family.
But on February 24, his body was found near a golf club in Pitt Town in Sydney's northwest.
Police suspect the perpetrators aimed to abduct a relative of Sydney businessman Dimitri Stepanyan, who lived on the same street as Mr Baghsarian, with the hope of receiving a $50 million ransom.
Investigators believe Mr Baghsarian was killed on the night of February 14 at a makeshift stronghold in Dural, about a half-hour drive from where his remains were found.