Waikato woman Christine King was last night found guilty of the manslaughter of her former husband in 1988.

But a jury in the High Court at Hamilton, after deliberating for 7 1/2 hours, found the 51-year-old not guilty of the murder of her then-husband Wayne Roycroft.

The prosecution said that King killed Mr Roycroft in 1988 by feeding him an overdose of sleeping pills and then buried his body in the garden of their home at Waihou, 42km northeast of Hamilton.

King admitted giving him the pills to make him go to sleep after suffering years of abuse at his hands, but said she did not believe they would kill him.

King buried Roycroft beneath the home's veranda, but the body was later exhumed and burned on a bonfire.

King was denied bail by Judge Ron Young and will be sentenced on December 16.

The reaction was hushed when the verdict was read out, but King's lips were visibly quivering.

When asked if the verdict represented closure, Aaron Roycroft, the youngest of eight brothers, said: "It does in a way, no one's a winner. We have lost a brother and they have lost a mother."

He said it was 18 years to the day since Wayne Roycroft disappeared.

His mother, Aileen, said sitting through the trial and hearing some of the evidence had been "terribly difficult".

King's family, particularly her daughters, remained calm afterwards and filed out of the courtroom without commenting.

The public gallery remained packed when the verdict was returned at 10.45pm, despite the wait of more than seven hours after the jury first left for deliberation at 3.17pm.

King's counsel, Judith Ablett Kerr, had argued that King was guilty only of manslaughter.