DNA taken from a suspect or an offender is added to a DNA database. There is no provision for that information to be removed from the system.
This means that where a person was questioned in relation to a serious offence and a DNA sample taken, that sample will remain on the database even if no charges were ever laid.
There are also no provisions to destroy DNA samples taken from people charged with an offence who are then subsequently acquitted [see Criminal Law (Forensic Procedures) Act 2007 (SA) s 40 for a list of DNA data base systems and indexes of DNA profiles].