A homicide investigation has been launched in south Auckland after the fatal stabbing of a 29-year-old woman at a Manurewa address overnight.

Counties Manukau police were called to an altercation at a party at the address and discovered a woman's body.

The dead woman did not live at the address, TV3 reported.

A 32-year-old woman will appear in the Manukau District Court tomorrow charged with assault.

A police spokesman said inquiries were continuing and more serious charges could follow.

Anyone who was at the party was asked to contact police.

Twelve other people were taken into custody but have since been released, TV3 reported.

Child, Youth and Family were also called to the scene and removed six children and two teenagers.

Neighbours told 3 News parties were frequently thrown at the house, but last night's was bigger and louder than usual.