Cory Jefferies has been found guilty of murdering his long-time partner Kim Richmond.

Jefferies, 46, has been on trial in the High Court in Hamilton, for the murder of 42-year-old Richmond in 2016.

The guilty verdict was returned at 11am following a week long trial at the High Court in Hamilton.

Her body was discovered in Lake Arapuni in June 2017, 10 months after she disappeared.

A police interview conducted just over two weeks after Ms Richmond was reported missing was shown in court.

In it, Jefferies is seen telling police he had never threatened or beaten her because he was not that sort of person.

When told that other people reported he had threatened her, Jefferies said that it was not true.

He told police she drove off in their ute shortly after they arrived home from a social function.

And said he saw her turn at the end of the drive and that was the last he ever saw of her.

He said he started texting her from the next morning but got no reply.

Jefferies admitted manslaughter but denied her murder.

His defence lawyer Thomas Sutcliffe told the jury in his closing address on Friday that Richmond's death was a spontaneous, unscripted event.

The Crown argued that her death was premeditated and was the violent product of the relationship problem the couple were facing.

Prosecutor Ross Douch said the treatment of Ms Richmond at the time of her death shows the depth of disdain Jefferies felt for her.