News · Criminal law explainer
Can police take your DNA in NSW?
DNA has become central to modern investigations, and people are often asked, or ordered, to give a sample. In New South Wales the rules are in the Crimes (Forensic Procedures) Act 2000 (NSW). This note explains when police can take your DNA, the difference between consent and an order, your rights during the process, and what happens to the sample afterwards.
By Aaron Kernaghan · Published 3 September 2026
Sometimes. In NSW police can take a DNA sample under the Crimes (Forensic Procedures) Act 2000, but they need a proper basis: your informed consent, an order by a senior police officer for a person in custody, or a court order. A simple mouth swab is the usual method. You should get advice before consenting, because a sample can go onto the DNA database.
When can police take your DNA?
There are three main routes. Police can take a sample with your informed consent. For a person who is in lawful custody and suspected of an offence, a senior police officer can order a forensic procedure in defined circumstances. For other cases, or where consent is refused, police can apply to a court for an order.
A DNA sample is usually taken by a buccal swab, a swab from the inside of the cheek, which is treated as a non-intimate procedure. More intrusive procedures have stricter rules and generally need a court order.
Do you have to consent?
No. Consent must be informed and voluntary, and you can refuse. If you refuse, police cannot simply take the sample on consent; they must rely on a senior officer's order or a court order, each of which has its own requirements.
Because a sample once taken can be analysed and stored, it is worth getting advice before agreeing. You are entitled to ask why the sample is sought and on what basis.
What are your rights during the procedure?
The Act builds in safeguards. You must be given information about the procedure and your rights, the process should be recorded where practicable, and the procedure must be carried out in a way that respects privacy and dignity. Special protections apply to children and vulnerable people.
If a forensic procedure is carried out without a proper basis, or the safeguards are not followed, the evidence obtained may be open to challenge. How the sample was taken can matter as much as the result.
What happens to the sample?
A DNA profile derived from a sample can be placed on the DNA database and matched against other profiles and crime-scene samples. There are rules about how long samples and profiles can be kept, and when they must be destroyed, for example where a person is not charged or is acquitted.
This is why consent is a real decision. A sample given today can have consequences well beyond the matter at hand.
What should you do if police ask for your DNA?
Stay calm and ask on what basis the sample is sought. You can decline to consent and ask to speak to a lawyer. If a senior officer's order or a court order is relied on, advice can help ensure the process is proper.
For anyone in custody, DNA is one of several issues that arise quickly. Our note on your rights in police custody covers the wider picture, and the recorded interview note explains the right to silence.
Frequently asked.
Can police force me to give a DNA sample in NSW?
Not on consent alone. If you refuse, police must rely on an order by a senior police officer, for a person in custody, or a court order, each with its own requirements under the Crimes (Forensic Procedures) Act 2000 (NSW).
How do police take DNA?
Usually by a buccal swab, a swab from the inside of the cheek, which is treated as a non-intimate forensic procedure. More intrusive procedures have stricter rules and generally require a court order.
Do I have to consent to a DNA test?
No. Consent must be informed and voluntary and you can refuse. It is worth getting advice before consenting, because a profile can be placed on the DNA database.
What happens to my DNA sample?
A profile can be placed on the DNA database and matched against other profiles and crime-scene samples. There are rules on how long samples are kept and when they must be destroyed, for example if you are not charged or are acquitted.
Can DNA evidence be challenged?
Yes. If a forensic procedure was carried out without a proper basis or the statutory safeguards were not followed, the evidence obtained may be open to challenge.
To speak to a criminal defence lawyer, call Aaron Kernaghan on 0421 717 019.
This article is written by Aaron Kernaghan, criminal defence lawyer at Good Legal Lawyers, as at 3 September 2026. It is commentary and reflects the personal opinion of the author only. It is not legal advice, it is not a substitute for advice on your own matter, and it does not purport to be accurate or complete. Any matter referred to may be before the court and any person charged is presumed innocent. For advice on a specific matter, contact Aaron Kernaghan on 0421 717 019 or contact the firm.
More criminal-law commentary by Aaron Kernaghan.
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