A third man was arrested on Friday in connection with the gang rape, murder and mutilation of Bredasdorp teenager Anene Booysen, Western Cape police said.
Captain Frederick van Wyk said the 23-year-old man, from the same area, was arrested at 9.30am.
"He will be charged and will also appear in the Bredasdorp Magistrate's Court on Monday."
Two other men, aged 21 and 22, were already in police custody, facing murder and rape charges.
National Prosecuting Authority (NPA) Western Cape spokesperson Eric Ntabazalila said the 21-year-old would appear in court on Monday. Once the man had appeared, the case would be postponed to Tuesday to coincide with the appearance of the 22-year-old, who Booysen identified shortly before she died in hospital.
He made his first court appearance earlier in the week.
Booysen (17) was left for dead at a construction site near her home, in the early hours of Saturday morning, after visiting a sports bar. She had reportedly worked as a cleaner for Asla Construction.
Her aunt Wilma Brooks wept when describing Booysen's injuries to the Cape Argus.
"Her throat had been slit, all her fingers and both legs were broken, a broken glass bottle had been lodged in her, her stomach had been cut open... That which was supposed to be inside her body lay strewn across the scene where they found her," she said.
Police said Booysen died in hospital around 10pm on Saturday.
Her death provoked outrage from all sectors of society.
The Congress of SA Trade Unions was planning to deliver a memorandum to the Bredasdorp police station after Booysen's memorial service on Sunday.
Provincial Cosatu secretary Tony Ehrenreich said they would picket outside the magistrate's court on Tuesday to support Booysen's family and "display our disgust at this cowardly act".
The Young Communist League of SA described the crimes as "stomach churning".
"We call, as an immediate measure, for a police officer in every police station nationwide to receive extra training around rape and sexual violence," spokesman Khaya Xaba said.
"It is abhorrent that women reporting rape are often met with incredulous smirks by police. Police must be seen to be taking rape very seriously."
On Thursday, President Jacob Zuma described the crime as "shocking", "cruel" and "inhumane".
"Impose the harshest sentences on such crimes, as part of a concerted campaign to end this scourge in our society," he said.
"It has no place in our country. We must never allow ourselves to get used to these acts of base criminality to our women and children."