Police believe that Narde traveled the 250 miles from Tamworth to St Leonards for the conference with the sole goal of seeing his former girlfriend, with whom he had a tumultuous on-again, off-again, long-distance relationship for several years.
Investigators are appealing for more information about Dr Reddy and her whereabouts before her death, including any sightings, her mood and what she was wearing.
Narde was killed in a head-on collision on Monday, which police suspect to have been a deliberate act, according to ABC News.
The last images police have gathered of Dr Reddy show she was in a McDonald's on George Street in the CBD about 2.15am Sunday, as mardi gras celebrations took over the city.
A Facebook page set up to help find Dr Reddy said it was "highly out of character for Preethi to not contact family and loved ones".
Police were told she last made contact with her family at about 11am on Sunday, saying she planned to head home after having a late breakfast in Sydney.
The Glenbrook dental surgery where Preethi Reddy worked was closed on Wednesday.
Gonzalo HIGUAIN scores opening goal for Chelsea in win against Fulham
Liverpool legend Graeme Souness says Chelsea boss Maurizio Sarri should not have recalled Kepa Arrizabalaga for their win at Fulham .
The police reports states, she was stabbed numerous times which lead to her death.
The Sydney Morning Herald reported Preethi's friends as saying that she was firm on her decision to break-up with Harsh several years ago, but the latter did not accept it.
"Glenbrook Dental Surgery staff are in mourning to hear the sad news about Preethi Reddy", the post read.
Dengate said Strike Force Carlwood officers investigating the case were unsure where and when Dr Reddy was murdered but were working on the probability she was killed at the hotel.
The pair weren't in a relationship at the time but had been previously, Detective Superintendent Gavin Dengate said on Wednesday.
"Words can not capture the pain we are feeling with the passing of my handsome big sister".
Preethi's disappearance is "out of character" and there are serious concerns over her welfare, a New South Wales (NSW) Police spokeswoman said.
"I ask you all to think about her family right now and about giving them the space to actually to be in this space".