Collie woman Debra Jane Alicia Holmes' trial has been dismissed

A Bunbury Supreme Court jury has been discharged on day three of a murder trial.

Debra Jane Alicia Holmes, 54, pleaded not guilty to murdering her partner Wayne Chappell, 56, after he was found dead from a gun shot wound on July 15, 2018.

The trial was expected to run for three weeks, with 30 witnesses to take the stand.

On Thursday morning, Judge Derrick discharged the 14 person jury for legal reasons "not appropriate to explain".

Mr Derrick thanked the jury for their assistance.

Ms Holmes has been remanded in custody to reappear on December 19 in the Perth Supreme Court, where a new trial date will be set.