A court has heard graphic details of a brutal beating suffered by a Christchurch teenager before he died.
Gavin Gosnell is accused of murdering Hayden Miles in a central Christchurch flat in August 2011 and has denied the charge at the beginning of his trial on Monday.
The Crown told jurors at the Christchurch High Court that the 15-year-old was subjected to a prolonged and brutal assault at the hands of Mr Gosnell, 28.
Prosecutor Barnaby Hawes said after befriending Mr Gosnell's girlfriend, Nicolette Vaux-Phillips, Hayden Miles would regularly meet her either during school or after school to drink with her.
Mr Hawes told the court that, on the day in question, the teenager had been drinking at the flat in Cashel Street Ms Vaux-Phillips and Mr Gosnell shared before a series of events that led to the assault.
The jury was told Hayden Miles was mugged by a friend of Gavin Gosnell's. When the boy confronted Mr Gosnell about it, the accused began "a prolonged and brutal assault" in several rooms.
The Crown alleges the following day when Hayden Miles was found dead in the living room, Gavin Gosnell dismembered the body before burying parts in two cemeteries in central Christchurch.
The jury was told the boy's remains were found in an unmarked grave in a Linwood cemetery four months after he was killed.
In evidence on Monday, Nicolette Vaux-Phillips, 19, said Hayden Miles was upset about being mugged and provoked Gavin Gosnell. She said the accused laughed while kicking and beating the boy in the head and stomach.
Defence lawyer Craig Ruane told the jury he was not suggesting for a moment that Gavin Gosnell should be found not guilty. Instead, he said the case is an issue of whether he should be convicted of manslaughter, not murder.
In 2012, an 18-year-old woman was sentenced to 12 months' home detention after pleading guilty to being an accessory to culpable homicide.
Justice Chisolm told the jury on Monday the case is likely to take up to three weeks.