The family of a Northern Cape woman murdered last week are calling for the swift arrest of the man they say killed her.

Kerileng Matlhoko was stabbed to death and found three days later by a local crime prevention group in Galeshewe, Kimberley. Relatives say her body was in an advanced state of decomposition, which has delayed the funeral.

Her uncle, Kabelo Matlhoko, said Ms Matlhoko leaves behind three young children.

"This young man has devastated the family itself," he said. "There are families around South Africa who are calling every day because they are heartbroken at this level."

He added that forensic findings showed the body was badly decomposed and that relatives want the law "to take its course to its fullest might".

"After our child then who else? You don't feel the pain until it happens to you," he said. "We have been seeing this GBV thing not taking it seriously, but now it has hit home."

Police have not yet publicly confirmed an arrest. The family say the suspect is her boyfriend.