Police spokesperson Sergeant Martin Xuma said Ngakatau visited his girlfriend, Pulane Marige, in the early hours of the morning on April 3, 2005, at her home.
Marige was drinking beer with her brother, her sister-in-law and a man called Babys. Ngakatau went into a jealous rage and demanded to know if she was in love with Babys.
He insisted she accompany him to his parents' house and on the way began beating and kicking her.
Xuma said Marige was screaming and was dragged into an open veld.
"Erick Ngakatau questioned her again and when Pulane Marige denied ever being in love with Babys he then assaulted her again as they reached the open veld."
After the assault, she was unable to stand and was unresponsive.
"The suspect then showed the Police and EMS where the girlfriend's body was. The victim was declared dead on the scene by EMS. The suspect was then detained at Selosesha Police Station."
Xuma said the case against Ngakatau was initially withdrawn and he disappeared.
Police were only able to trace him just over a year ago.