Hung jury in Zanker murder trial

A Sydney jury has been discharged after being unable to reach a verdict about a man accused of murdering cannabis labourer Jacob Munro.

Shaun "Shorty" Steven Zanker, 27, pleaded not guilty to the July 2014 murder of Jacob Munro, whose body was found months later in a grave at Bulahdelah State Forest, north of Newcastle.

After several days of deliberations, the jury on Thursday told Justice Desmond Fagan they were unable to reach a unanimous or majority verdict.

The prosecution alleged Zanker planned with cannabis plantation co-workers Stanley Forward, Donald Cameron and David Ian Wilkinson to kill Mr Munro, even though Zanker did not actually stab him to death.

Forward and Cameron pleaded guilty to the murder and Wilkinson pleaded guilty to being an accessory and all three have been sentenced.

Zanker's defence said Zanker was unaware of a plot to kill Mr Munro, and that even when his colleagues told him they were going to dig a bush grave in preparation for a body, he did not believe they were serious about murder.

Zanker will appear in court on Friday for a new arraignment date to be set and to be sentenced for outstanding cannabis cultivation offences to which he has pleaded guilty.