She has been remanded in custody for sentencing next month.
Now, it has been revealed that the bar worker was arrested on March 25 for possession of marijuana on a farm in Middelburg - a large farming and industrial town in the South African province of Mpumalanga.
Middelburg police spokesman, Captain Khanyisile Tshwane told South Africa news outlet Rapport that Cilliers and two other people were arrested and appeared in a magistrates court the following day.
She later skipped bail and a warrant had been issued for her arrest, it was reported.
The case against the other two suspects has since been withdrawn, Captain Tshwane told Rapport.
A South African Consulate representative was at court for her appearance in Christchurch yesterday.
Judge David Saunders told Cilliers, who appeared via video-link, that the consulate would want to talk to her before she is sentenced.
It is not clear whether she would be sent home to face drugs charges once she had been sentenced in New Zealand.