Right to Know Grounds of Arrest in South Australia
Reviewed by the Commoner Law Editorial Team. Sourced from Commonwealth Acts of Parliament, federal regulations, and official government guidance. State-level information reflects each state's own Acts and court decisions. Written in plain language for general understanding — this is educational content, not legal advice. Our editorial standards
What is this right?
Under section 3W of the Crimes Act 1914 (Cth), an AFP officer may arrest without a warrant only on reasonable grounds to believe you're committing or have committed a Commonwealth offence — and only where arrest is reasonably necessary for a defined reason (court appearance, preventing further offences, preserving evidence, and so on).
At the time of arrest, the officer must tell you the grounds. That's a common-law requirement going back to Christie v Leachinsky, reinforced by s. 23F of the Crimes Act, which requires the caution and the information about your rights to be given on the spot.
If the officer doesn't tell you why, the arrest may be unlawful. An unlawful arrest can lead to evidence being excluded at trial and a civil claim for wrongful arrest. Australian courts treat the requirement seriously.
When does it apply?
This right applies whenever an Australian Federal Police officer arrests you for a Commonwealth (federal) offence.
- It covers offences under federal laws such as the Crimes Act 1914, the Criminal Code Act 1995, drug importation laws, and fraud against the Commonwealth.
- It applies to all people in Australia, including citizens, permanent residents, and visitors.
- State and territory police have similar obligations under their own laws, but this right specifically covers federal arrests.
What to Do If Australian Federal Police Arrest You Without Explaining Why
- Ask clearly: "Why am I being arrested?" and "What offence am I being arrested for?"
- Listen carefully to the officer's response and try to remember or write down their exact words.
- Ask for the officer's name and badge number.
- Stay calm and cooperate physically while noting any concerns.
- Ask to speak to a lawyer as soon as possible.
What should you NOT do?
- Don't physically resist the arrest, even if you believe it is unlawful. You can challenge it later in court.
- Don't argue or become aggressive — this can lead to additional charges such as obstruction/resisting a Commonwealth official under s 149.1 of the Criminal Code Act 1995 (Cth) (maximum 2 years imprisonment). Note: s 7A of the Crimes Act 1914 does not create a resisting arrest offence.
- Don't assume you must answer questions just because you have been arrested — you still have the right to silence.
- Don't sign anything or make a statement before speaking with a lawyer.
How South Australia differs from federal law
In South Australia, police powers of arrest are governed by the Summary Offences Act 1953 (SA) and common law principles. Under section 75 of the Summary Offences Act, a police officer may apprehend without warrant any person found committing or reasonably suspected of having committed an offence.
- The arresting officer must inform you of the reason for your arrest at the time of arrest or as soon as practicable afterwards. Failure to do so may render the arrest unlawful.
- South Australia also uses the Criminal Law Consolidation Act 1935 (SA) for arrest powers relating to serious indictable offences.
- SA Police must consider whether arrest is necessary — officers are encouraged to use alternatives such as issuing a summons or police expiation notice rather than arresting for minor offences.
- If arrested unlawfully, you may have grounds for a claim of false imprisonment against the South Australia Police (SAPOL).
Additional Steps in South Australia
If you believe your arrest was unlawful, obtain legal advice from the Legal Services Commission of SA (1300 366 424) or Aboriginal Legal Rights Movement (ALRM) for Aboriginal and Torres Strait Islander people. Complaints about police conduct go to the Police Complaints Authority (pca.sa.gov.au) or ICAC.
Relevant Law: Summary Offences Act 1953 (SA), s 75; Criminal Law Consolidation Act 1935 (SA); Police Complaints and Discipline Act 2016 (SA)
Common Questions
When does right to know grounds of arrest apply?
This right applies whenever an Australian Federal Police officer arrests you for a Commonwealth (federal) offence.It covers offences under federal laws such as the Crimes Act 1914, the Criminal Code Act 1995, drug importation laws, and fraud against the Commonwealth.It applies to all people in Australia, including citizens, permanent residents, and visitors.State and territory police have similar obligations under their own laws, but this right specifically covers federal arrests.
What should I do if the Australian Federal Police arrest me without telling me the reason?
Ask clearly: "Why am I being arrested?" and "What offence am I being arrested for?"Listen carefully to the officer's response and try to remember or write down their exact words.Ask for the officer's name and badge number.Stay calm and cooperate physically while noting any concerns.Ask to speak to a lawyer as soon as possible.
What mistakes should I avoid with right to know grounds of arrest?
Don't physically resist the arrest, even if you believe it is unlawful. You can challenge it later in court.Don't argue or become aggressive — this can lead to additional charges such as obstruction/resisting a Commonwealth official under s 149.1 of the Criminal Code Act 1995 (Cth) (maximum 2 years imprisonment). Note: s 7A of the Crimes Act 1914 does not create a resisting arrest offence.Don't assume you must answer questions just because you have been arrested — you still have the right to silence.Don't sign anything or make a statement before speaking with a lawyer.
Right to Know Grounds of Arrest in other states
Same topic, different jurisdiction. Pick the one that applies to you.