Hung jury in Sydney murder trial

The jury in a trial of a man accused of murdering his pregnant girlfriend at a Sydney apartment have been discharged after saying they were unable to reach a verdict.

Allira Green was five months pregnant with a boy when she died from a single stab wound to her chest in the early hours of August 3, 2013.

Her partner Christopher John Anderson, then 39, pleaded not guilty to her murder, saying he was acting in self-defence and had been trying to "rescue" the 23-year-old and his unborn child from her ice addiction at the time.

On Tuesday after more than 10 hours of deliberations, the Supreme Court jury said they were unable to reach a verdict.

This was after Justice Lucy McCallum directed them that they were able to return a majority verdict, rather than a unanimous one.

But when they returned and said they could not be swayed, she discharged them, saying a hung jury was not a failure of the justice system but showed they were hard working.

It's expected Anderson, who has been in custody throughout the trial, will apply for bail on Friday.