Preethi Reddy's body was found stuffed in a suitcase in her auto parked in an eastern Sydney street, New South Wales Police said.
Numerous patients of Reddy posted messages of condolences for her family on the surgery's Facebook page.
"I'll see you again one day...and we'll continue where we left off my angel", he wrote.
The bag contained the body of his former girlfriend Preethi Reddy.
The head-on collision, around 340 kilometres from where Reddy's body was found, is believed to have been deliberate, they said.
Her sister, Nithya Reddy, posted on Facebook that she had previously been located at Hotel Urban in Greenwich on Sydney's lower north shore.
At a press conference this morning, Detective Superintendent Gavin Dengate revealed investigators questioned Dr Narde on Dr Preethi's whereabouts when the case was still a missing persons inquiry.
Narde died after his BMW vehicle collided with a truck on the New England Highway on Monday night, a day after his ex-girlfriend was reported missing, New South Wales Police (NSW) said.
In a statement released on behalf of Dr Reddy's family, her sister, Nithya, said: "Words can not capture the pain we are feeling with the passing of my lovely big sister".
Reddy was last seen waiting in line at McDonald's in George Street on Sunday, the police said.
She last spoke with her family at about 11am on Sunday, and nothing seemed amiss.
She was not seen or heard from since.
Dr Reddy drove her VW Golf, registration, DFP 78P, throughout the weekend.
Anyone with information should contact Crime Stoppers on 1800 333 000.
"I knew they were in a long-term relationship, many of us did".
"It is with great sadness we announce the tragic passing of our beloved Harsh", the post read.
"Words can not capture the pain we are feeling with the passing of my attractive big sister", said Nithya, Preethi's sister.
Dr Reddy's parents and sister were beside themselves with grief as they tried to process the disturbing death of their "lovely girl", he said. Her father Narasimha Reddy teaches at Western Sydney University.
"Words can not capture the pain we are feeling with the passing of my handsome big sister", Nithya said.
"Prior to this unthinkable event, she had been the happiest I'd ever seen her - she was living her best life".
Her previous rejections had failed to deter the "obsessed" Narde, police believe.
Nithya also extended her thanks to the media for their assistance, but also called for respect for the family.
"We ask that everyone keep that in mind that we are grieving and we need space to do that". Our family will never be the same without Preethi our lives.
"Please let her attractive soul rest in peace".