Section 17: Power to investigate crimes
Statutory text (Thai original)
พนักงานฝ่ายปกครองหรือตำรวจมีอำนาจทำการสืบสวนคดีอาญาได้
English translation
Administrative or police officials shall have the power to conduct investigations into criminal cases.
This English translation is provided for reference only and has not yet been firm-verified. Always rely on the Thai original.
Firm annotation
Section 17 opens the chapter on the power of investigation and inquiry with the base rule: administrative and police officials may investigate criminal cases. Investigation here is the Thai concept of sueb suan, the fact-finding and detective stage, which the Code treats separately from the formal inquiry (sob suan) governed by later sections. Unlike inquiry, which is tied to territorial jurisdiction, investigative power is broad, but it depends on the officer actually holding office. The section works together with the definitions in Section 2 and with the arrest, accusation, and inquiry provisions that follow.
Why this matters in practice
The key practical point is that investigative authority belongs to a serving official; a suspended or otherwise not-in-office officer has no Section 17 power, which can undermine anything built on their acts. Investigation is also nationwide in reach, so an officer is not confined to the station where they are posted, unlike the territorially limited inquiry power. If your case turns on whether the investigating officer was validly in office or acting within authority, a licensed Thai lawyer can review the appointment and command records.
Supreme Court decisions interpreting this section
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Supreme Court Judgment No. 5182/2559 (2016)
An officer who has been suspended from duty and is not performing police functions has no power to investigate criminal cases under Section 17 during that period.
Because the first defendant had been suspended from December 2008 until he reported back to duty in August 2010, the Court held that during that gap he was not performing police duties and therefore had no power under Section 17 to investigate or to arrest.
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Supreme Court Judgment No. 13537/2553 (2010)
A police officer has the power under Section 17 to investigate criminal cases; once investigation reveals the details of an offense and identifies a suspect, the officer may lodge an accusation under Sections 2(8), 17, 18, 125, and 127.
The Court held that the officer's acts fell within his authority: as a police officer he had power to investigate the case, and having found the plaintiff to be a suspect connected to illicit fuel trading, he could lawfully lodge an accusation and, once appointed to the investigation team, gather all available evidence.
Curated decisions with case numbers verified against the Supreme Court database. English renderings are the firm's editorial translation for study.
Cited in 19 Supreme Court decisions (1943 to 2016)
Selected citing decisions
- Decision 5182/2559 (2016)
- Decision 13535/2553 (2010)
- Decision 7008/2548 (2005)
- Decision 133/2548 (2005)
- Decision 10561/2546 (2003)
- Decision 6471/2543 (2000)
- Decision 6880/2541 (1998)
- Decision 500/2537 (1994)
This list is selected automatically, weighted towards judgments that turn on this section rather than ones that merely recite it when passing sentence. It has not yet been reviewed by the firm.
Most often cited alongside
- Thai Penal Code s. 83 8
- Section 2 8
- Thai Penal Code s. 91 6
- Thai Penal Code s. 157 6
- Thai Penal Code s. 149 5
- Thai Penal Code s. 78 4
Sections that appear in the same judgments as this one most often. The figure is the number of decisions.
Counted across the firm's corpus of 83,652 Supreme Court decisions, 1921 to 2026. The count is complete; the stated year range trims rare outliers so it describes where the citations actually sit. These figures are computed by us and are not official court statistics. How we count these, and what we measured
Frequently asked questions
What is the difference between investigation and inquiry in Thai criminal procedure?
Investigation (sueb suan) under Section 17 is the fact-finding stage and has broad, nationwide reach. Inquiry (sob suan) is the formal case-building process by an inquiry official and is tied to territorial jurisdiction under later sections.
Can a police officer who is suspended from duty investigate a criminal case?
No. Section 17 grants investigative power to serving officials. An officer who has been suspended and is not performing police duties has no power to investigate during that period.
Cite this section
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Plain citation
Criminal Procedure Code, s. 17 (Thailand) -
Academic citation
Criminal Procedure Code (Thailand), s. 17. ThaiLawOnline, https://www.thailawonline.com/thai-criminal-procedure-code/section-17/ (accessed 11 August 2026). -
Thai citation
ป.วิ.อ. มาตรา 17 -
Permalink
https://www.thailawonline.com/thai-criminal-procedure-code/section-17/ -
Embed on your site
<blockquote cite="https://www.thailawonline.com/thai-criminal-procedure-code/section-17/"><p>Administrative or police officials shall have the power to conduct investigations into criminal cases.</p><footer>Criminal Procedure Code, s. 17 (Thailand) — <a href="https://www.thailawonline.com/thai-criminal-procedure-code/section-17/">ThaiLawOnline</a></footer></blockquote>
The Thai text is authoritative. The English is an unofficial translation by ThaiLawOnline, free to reuse with attribution.