One minute before she fell 15 storeys to her death, Lisa Harnum's fiance was caught on camera dragging her "very violently" back into their apartment, a Sydney magistrate has been told.

Within one minute and eight seconds, the Canadian-born dancer was lying dead on the pavement outside her high-rise Sydney apartment block, Downing Centre Local Court heard on Monday.

Her fiance, Simon Gittany, 39, has pleaded not guilty to murdering Ms Harnum, 30, by pushing her off the balcony of their apartment in Sydney's CBD in July 2011.

He faced a hearing on Monday to decide whether there was enough evidence to commit him to stand trial.

The officer in charge of the investigation, Detective-Sergeant David Weekes, told the court Gittany was seen on CCTV camera dragging Ms Harnum "very violently" back into the apartment, while a neighbour told police she heard a woman screaming, "God help me, help me".

Footage played in court showed Ms Harnum struggling with her fiance at the door of their 15th floor unit.

"The accused comes out behind her, puts one arm around her neck and a hand around her mouth and pulls her back into the apartment," crown prosecutor Daniel Noll told the court.

One minute and eight seconds later, Gittany re-emerged from the apartment before returning briefly to put on a shirt and then taking the lift down to the ground floor.

"At that point, we say the deceased is dead on the pavement below," Mr Noll said.

None of Ms Harnum's fingerprints were found on the balcony ledge, the court heard.

A 15-year-old boy who saw Ms Harnum land on the ground initially spoke to police, but his parents did not give permission for him to make a formal statement.

"(The boy said) he looked up and saw a male standing on a balcony halfway up the building," Det Sgt Weekes said.

"The male was not wearing a shirt."

Inside the apartment, police discovered a packed travel bag containing Ms Harnum's passport and a prescription for sleeping tablets, the court heard.

Anthony Bellanto, QC, representing Gittany, said the side-effects of the sleeping pills included hyperactivity and irrationality.

"The deceased also unfortunately suffered from bulimia," Mr Bellanto said.

He said police had put forward a number of scenarios as to how Ms Harnum met her death.

"It's a matter of some speculation as to how precisely she managed to get over the balcony and fall," he said.

He put it to Det Sgt Weekes that Ms Harnum could have used a running machine or a pot plant on the balcony as a stepping stone to get onto the balustrade.

"I disagree with you," Det Sgt Weekes replied.

The hearing will resume before Magistrate Clare Farnan on Tuesday.