The trial of a man accused of killing his partner and dumping her vehicle, with her body inside into a South Waikato lake opens in the High Court in Hamilton this morning.

Cory Jefferies, 46, is charged with the murder of his long-time partner, Kim Richmond, who was 42.

Kim, who had three children with Jefferies, was first reported missing from her Arohena home, near Te Awamutu in August 2016, but her body was not discovered until 10 months later in June 2017.

Her vehicle, a Ford Ranger utility was recovered by police divers from Lake Arapuni, not far from her home.

Police had carried out extensive searches for Ms Richmond prior to her body being discovered.

These included previous searches of the hydro lake and further afield.

In October 2016, two of her banks cards were found along a roadside near Rangipo in the central North Island.

Jefferies was arrested and first appeared in the Hamilton District Court on the day of Kim's funeral on 20 June last year.

He pleaded not guilty to murder and has been on electronic bail, with a number of conditions, which were suppressed, after appearing in the High Court in Hamilton in July last year.