The 34-year-old Zimbabwean was arrested in King William's Town, Eastern Cape, within 24 hours of the killings, believed to have happened on Tuesday night in Elliotdale, 225km away.
"He was in hiding at the time of his arrest and allegedly preparing to flee the country," said Cele.
The bodies of Nomzamo Mhlanti, 42, and her five children — Azakhiwe, 10, Yibanathi, 8, twins Wineka and Thoko, 5, and six-month-old Luphumlo — were discovered Mhlanti's eldest son, Balungile, 16, on Wednesday.
They were lying on the floor of their shack in Sidebekweni village, and scattered nearby where photographs with the faces of the deceased scratched out.
In a statement on Saturday, Cele said the family was attacked and killed with an axe, believed to be the same weapon found at the crime scene.
Eastern Cape police commissioner Lt-Gen Liziwe Ntshinga described the incident as shattering.
“It is inconceivable that just at the opening day of the 16 Days of Activism we can wake up to such a horrible and distressing incident. Whoever is behind these gruesome and heartless murders must be found without any delays,” Ntshinga said.
Cele said while it was the responsibility of the police to bring killers to justice, "such arrests only come after the fact, and in many instances it is after lives are destroyed and lost".
He added: "I am making a call to men, I urge you all to stop brutalising and violating women and children … it’s that simple.”
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