Meraj Zafar, 20, turned himself in at Bankstown police station on Monday afternoon following a public appeal for information.
Detectives and his lawyer Mohamad Sakr have confirmed Zafar was in a relationship with Armina Hayat before she was found dead in the North Parramatta unit block.
After forcing their way into the home, police found the woman's body in the bathroom with hazardous chemicals causing them to retreat from the scene.
Specialist HAZMAT officers from Fire and Rescue NSW spent several hours at the apartment, where biohazard bags could be seen on Monday afternoon.
The 20-year-old did not appear in person or via AVL at his first mention in Bankstown Local Court on Tuesday before magistrate Shane McAnulty.
Zafar allegedly murdered Ms Hayat between Saturday and Sunday at North Parramatta, according to court documents.
His lawyer Mr Sakr told the magistrate there would be no application for bail on Tuesday but perhaps "in due course".
This could be as early as April 5 when Zafar's matter is next before a court where a brief of evidence is expected to be served.
Outside Bankstown court, Mr Sakr would provide no further comments as to the nature of the couple's relationship, or whether he was being supported by family.
"He's distraught about being in custody, it's just a matter of whether he wishes to fight these charges or not, but I will take those instructions and advise accordingly" Mr Sakr told reporters.
Police Superintendent Julie Boon said police who were checking on her welfare found "a very confronting scene" in the bathroom
"It was an absolutely awful scene," she told 2GB on Tuesday.
A truck was found shortly after Zafar's arrest nearby in Greenacre and was seized for forensic examination.
Police told AAP on Tuesday the type of chemicals found at the scene were still being analysed and yet to be determined.
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