A man who murdered his partner and buried her body under a slab of concrete on his parent’s property near Mannum in South Australia has been sentenced to at least 22 years’ jail.

Neil Archer, 31, pleaded guilty to murdering the mother of his young son Jody Meyers in August 2015.

The 20-year-old’s body was not found until about a month after she was reported missing.

Archer’s mother has been charged with helping him cover up the murder and is in custody awaiting trial.

The body of 20-year-old Jody Meyers wasn’t found until a month after she was reported missing. Photo: AAP/Facebook

Ms Meyers’ family last saw her on August 26, 2015 when she left a family barbecue celebrating her step-father’s birthday with Archer.

The court heard Archer strangled Ms Meyers with the cord from the grey hoodie jumper he was wearing.

Justice Trish Kelly said Archer thought Ms Meyer’s family was trying to break-up their relationship.

“When Jody’s brother-in-law suggested you had two options to either put up with it or leave, you responded with ‘I will just kill her’,” she said.

“That statement speaks volumes about your mindset.

“It betrays an attitude of a man who thinks he owns his partner’s life.

“It is unfortunately all too common in controlling, abusive men who end up killing their partners.”

As Archer was taken back into custody a member of Ms Meyer’s family yelled “rot you piece of shit”.

‘Monster killed the person he was meant to love’

During sentencing submissions in April members of Ms Meyers’ family read emotional victim impacts statements to the Supreme Court.

The young mother’s sister Tania Parsons said her family had accepted Archer at Jody’s request.

“You looked me in the eye and said you knew nothing, meanwhile you were thinking you had got away with murder,” she said.

“Not only did you take Jody’s life, but you buried her like she was disposable, like a piece of rubbish. How do you ever sleep at night?”

The tool shed where the body of Jody Meyers was found at Mannum. Photo: ABC/Supplied SA Police

During the same hearing, Ms Meyers’ brother-in-law Michael Bates described Archer as a “monster”.

“It’s the worst and the most horrible, disgusting, inhumane thing you could do, not just to a family but to your own family and child,” he said.

“He is a monster, there’s no other way to describe it, he’s killed the person he’s meant to love, the person he’s meant to protect, the person he told us all he will look after her and he didn’t do that.”

—ABC