LEGISLATION making it possible to collect DNA samples from suspects or convicted offenders is unlikely to be passed by Parliament any time soon.

Andrew Faull, researcher at the Institute for Security Studies, is among those who are asking what happened to the legislation, originally part of a 2009 bill.

He considers one of the most important developments in forensic investigation in recent decades to be the increased use of DNA evidence in investigating and prosecuting criminal offences.

Democratic Alliance MP and member of the portfolio committee on police Dianne Kohler Barnard said on Friday that the committee would first need to go on a study tour to Canada and the US to investigate international best practice on DNA databases before considering introducing such legislation in SA.

"We need to speak from an informed perspective," she said. The visit is scheduled to take place in July.

As legislation now stands in SA, criminal justice officials are not allowed to gather DNA samples, despite the process being relatively noninvasive.

Mr Faull said an important premise behind intelligence- driven policing was that a small percentage of offenders often accounted for a large percentage of all crimes.

The DNA database against which all crime-scene DNA evidence can be checked will help police in ensuring that they not only have a "tough" approach to crime, but also have smarter ways to investigate.

The building of the DNA database was originally part of the Criminal Law (Forensic Procedures) Amendment Bill of 2009 that also included the collection and storage of fingerprints, palm prints, footprints and photographic images for the purpose of fighting crime.

However, the portfolio committee on police decided to pass two separate laws - one for fingerprint collection and another for the DNA database.

The law governing the collection and storage of fingerprints was passed last year.

Ms Kohler Barnard said interested parties had raised several concerns about the building of a DNA database, ranging from fear that DNA could be stolen and used for profiling, to concern about the invasion of privacy.

She agreed that in the case of rape, it was often one person committing multiple rapes before finally being caught by police.

Mr Faull said it had also been shown that many criminals re- offended, and that career criminals often began by committing minor offences which increased in severity over time.

"Connecting a variety of otherwise disconnected crimes is relatively simple using DNA analysis, providing sufficient evidence is gathered from all crime scenes, crime victims and offenders, and stored in a DNA database," Mr Faull said.

"It is not difficult to imagine how DNA could revolutionise criminal investigations in SA."

Ms Kohler Barnard said one of the main challenges in the proposed legislation was to ensure the DNA database was secure, and that there was no opportunity for someone to remove a DNA sample and place it fraudulently at a crime scene to implicate someone else.