A High Court jury in Whanganui has heard that the man accused of murdering sickness beneficiary Marice McGregor will take the stand.

Dean Mulligan has pleaded not guilty at the murder trial. Ms McGregor died after being struck three times in the head with an iron bar last April, but her body wasn't found for almost three weeks.

Defence lawyer Stephen Ross says they'll tell the jury that no blood or DNA was ever found on the alleged weapon or in Mr Mulligan's vehicle.

He says Mr Mulligan will take the stand in his trial and tell the jury who he believes killed Ms McGregor

Crown Prosecutor Lance Rowe told the court that Ms McGregor and Mulligan met online 18 months before her death, and she believed him to be her boyfriend, despite the accused still living with his wife and children. He says she was murdered after she decided not to keep giving money to him.

He says Mr Mulligan confessed the murder to police, a friend, his priest and a stranger.

He told the court that the accused told police in an interview a few weeks after Ms McGregor's death that he flew into a rage and hit her a couple of times. He says the accused told police that he didn't go for help and wanted to make sure she was dead.

However, Mr Mulligan reworded his confession and relationship details with Ms McGregor multiple times throughout police interviews.

Lance Rowe says Mr Mulligan researched the consequences of hitting someone over the head, which he says shows that the killing was planned.

- Newstalk ZB