"I'll see you again one day ... and we'll continue where we left off my angel", Mr Vemula wrote.
Just two days beforehand, Dr Reddy's boyfriend had posted a message asking his friends to help in the search for his then-missing girlfriend.
"Super anxious", he wrote on March 4.
Preethi Reddy pictured at Woolloomooloo, in central Sydney.
She told them that she would head home after breakfast, and when she failed to return, her family contacted police.
Police found her auto parked on a street in Kingsford and discovered Reedy's body in a suitcase. Her body was found stuffed in a suitcase in her auto in a parking garage.
The 32-year-old from Penrith in western Sydney had been attending a dental convention at St Leonards over the weekend.
NSW Police superintendent Gaven Dengate tells Ray Hadley police questioned the man before was killed in a head-on collision with a truck on Monday night.
Preethi was captured on CCTV inside McDonald's at the Strand Arcade in central Sydney about 2.15 a.m. on Sunday and appeared to leave alone. Police officials said the man died in a vehicle crash on the New England Highway on Monday night, a day after Reddy was reported missing.
Police said her auto, a 2016 grey Volkswagen Golf Comfortline registration DFP78P, was a crucial piece of evidence.
"We are still working on the timeline of events and that's why we need the public to come forward with any information they have", he said.
In a media conference on Wednesday, an NSW Police spokesman confirmed that police had spoken to the ex-boyfriend, who has also been identified as a dentist, as part of the missing person investigation before he was killed on Monday.
The man suspected of murdering the Sydney dentist Preethi Reddy, whose body was found stuffed in a suitcase in her auto parked in an eastern Sydney street, New South Wales, is another Indian-origin dentist and her ex-boyfriend Harsh Narde, police said.
Investigators believe that Narde did not accept that, and had attended the weekend conference purely in order to see her.
"I knew they were in a long-term relationship, many of us did", he added.