The Indian family of a man suspected of murdering his ex-girlfriend and dumping her body in a suitcase were trying to arrange a marriage for him, according to a friend.

Key points: Harsh Narde was a key suspect in the murder of his ex-girlfriend Preethi Reddy

Harsh Narde was a key suspect in the murder of his ex-girlfriend Preethi Reddy He graduated from university in Bangalore in 2009 and began working in Tamworth three years ago

He graduated from university in Bangalore in 2009 and began working in Tamworth three years ago He died in a car crash the day after his former partner was reported missing

Tamworth dentist Harsh Narde is thought to have stabbed to death Preethi Reddy, whose body was found in Sydney's eastern suburbs on Tuesday night.

Dr Narde was killed in a fiery crash on the New England Highway on Monday — a day after Dr Reddy, his ex-girlfriend, was reported missing by her family.

Immediately after his death, tributes flowed for Dr Narde on social media, although some have now been deleted.

"Today, hearing the news of your death I was shocked," wrote Chaitanya Joshi, in a tribute posted from India before Dr Reddy's body was found.

"Since childhood, you were very brilliant as well as naughty but more than that you had an affable and amicable personality.

"Here at home, your parents had started looking at marriage proposals for you — we all were so happy at the prospect of you getting married."

Police said Dr Narde died in this crash, and that his car was on the wrong side of the road. ( Supplied: Rural Fire Service )

Arranged marriages account for a majority of marriages in India and it is not uncommon for family members to organise potential couplings on behalf of their son or daughter.

The president of the Federation of Indian Associations in ACT, Krishna Nadimapalli, said the arranged marriage process could cause conflict and pressure when a child was overseas.

"In some families, they will try and influence the boy or girl into an arranged marriage and it creates a lot of stress and misunderstandings," he said.

While Mr Nadimpalli said there was no research linking violence to the marriage process, young people were increasingly at odds with the orthodox elements of the process.

The stress, he said, in some cases could be extreme.

Police are investigating all aspects of the former couple's relationship, including how long they were together, and the circumstances of their breakup.

Crash was deliberate

Dr Reddy, who worked at a clinic in the Blue Mountains and lived in Penrith, was last seen at McDonalds in the Sydney CBD early Sunday morning.

She had attended a dental conference in the suburb of St Leonards at the weekend, where police said she had met with Dr Narde.

Her family last spoke with her at 11:00am on Sunday, and raised the alarm when she did not return home later that day.

Police interviewed her ex-boyfriend as part of their missing persons investigation.

Dr Narde worked at the Happy Smiles clinic in Tenterfield in New England and in September, 2016, he joined the Oasis Smiles Dental clinic in Tamworth.

Police are still appealing for information about Preethi Reddy's final hours. ( Supplied: Facebook )

Police believe the head-on collision, which occurred around 340 kilometres from where Dr Reddy's body was found, was deliberate.

After news of the fatal crash at Willow Tree, the Oasis Smiles clinic posted a tribute to Dr Narde on social media.

"It is with great sadness we announce the tragic passing of our beloved Harsh," the post, which has since been removed, said.

"We send our deepest sympathy and our love to his family in India."

Speaking on behalf of Dr Reddy's family, Navniit Anand — a friend of the victim's father — said the family had been in Australia for about two decades and was receiving lots of support.

"The family is shattered, they've lost a daughter … a lovely daughter," Mr Anand said.

"They're a wonderful family, I wish every family would be close-knit the way they are."