A Taupo man who killed his partner in an "unsurvivable attack" with a hammer has pleaded guilty to murder.
Martin Cranswick Schofield, 49, entered his plea in the High Court at Rotorua yesterday.
Schofield appeared calm in the dock and showed little emotion during the reading of the Summary of Facts.
Katrina Drummond, 47, was found dead in a bedroom of her Elizabeth St home in Taupo in April.
Rotorua Crown solicitor Amanda Gordon confirmed the pair were in a relationship at the time of the murder.
"[Schofield] and [Ms Drummond] were married for 12 years and had two daughters before separating and seeing other people for 17 years. In 2011, the pair reconnected and began living together unmarried, but as a couple."
Ms Gordon said Schofield became enraged on the day of the murder, after finding out Ms Drummond had been seeing somebody else.
"On April 14 [he] came home from work and joined [her] in the kitchen ... An argument began and [Ms Drummond] revealed she had been seeing somebody else.
"[He] grew enraged, storming out of the house ... he uplifted a Stanley knife, scratching derogatory words on [Ms Drummond's] car."
Ms Gordon said Schofield grabbed a hammer before re-entering the house.
"[He] found [Ms Drummond] in the bedroom and using the hammer, struck her on the back of her head with enough force to make her fall face-down onto the ground.
"[He] then proceeded to deliver at least seven more blows to the back of her head in what has been described, in a post-mortem report, as an 'unsurvivable attack'."
Ms Gordon said Schofield left the address after the attack and drove to the Taupo police station where he told a constable on duty he had killed his partner.
Justice Timothy Brewer, who appeared in court via video feed, set a sentencing date for September 2. Schofield was remanded in custody.