It's yet to be determined if a Tauranga man charged with murdering his father is fit to stand trial.

William Church, 22, appeared in the Tauranga High Court today by an audio-visual link from a mental health facility.

He is accused of fatally stabbing his father Michael Steven Church with a butcher knife at their Pāpāmoa East home on September 22.

Church's lawyer Rachael Adams told the court her client's mental health has deteriorated and his fitness to stand trial is now in question.

The defense has engaged a medical expert.

Crown prosecutor Richard Jenson says the Crown has also engaged a medical expert and is awaiting a written medical report.

Church is scheduled to face a two-week jury trial in the High Court in Rotorua beginning on October 7.

He has been further remanded into the care of the mental health facility.

Church will next appear for a pre-trial review on April 10.