Shaun King, 35, appeared briefly at Campbelltown Local Court on Thursday morning charged with the murder of his partner, Drew Douglas.
He did not apply for bail and it was formally refused.
Police previously said they received a phone call from a distressed man at a home in St Marys, in Sydney's west, on Tuesday about 8.40pm.
But officers did not attend the property about 6.45am on Wednesday, when the 31-year-old woman was discovered with fatal stab wounds.
The circumstances surrounding both the initial call and subsequent response is now the subject of a major internal investigation.
Assistant Commissioner Leanne McCusker said the police's lack of response to the Tuesday call and officers' subsequent attendance at the property would form part of the investigation.
"That timeline ... will certainly be very, very strongly looked at," she told reporters.
She added the circumstances surrounding the death would also be investigated, including whether there were any missed opportunities for police to act.
The NSW Law Enforcement Conduct Commission has also been notified and will monitor the investigation.
11°C