Criminal Law Overview

This is a very brief criminal law overview about Thailand. In Thailand the Criminal Procedure Act states who is an investigator and what their powers are. There are 2 types of investigators under Thai law with different powers. The persons and powers are identified under Section 2 and Section 17 of the Thai criminal procedure code. The second type of investigator falls under the Special Case Investigation Act B.E. 2547 (2004).

Criminal Law Overview

A police officer or administrative official can institute an arrest if they are a prison warden, an official of the Excise Department, Customs Department, Harbor Department, or an Immigration officer. They have the power to arrest wrong does as well as collect evidence in a criminal matter. Normal investigators as mentioned above investigate “normal crimes” however special investigators tend to only be used in Thailand for the following type of crimes.

(a) Complex criminal cases that require specialist inquiry special collection of evidence;

(b) Criminal cases that affect public order, national security, and finance;

(c) Serious transnational organized crime;

(d) Criminal cases that involve influential people and senior public officeholders.

The Acts which are normally covered in Thailand by special investigators are the following laws which normally requires specialist skills of investigation as well as evidence collection.

Acts investigated by special investigators.

1. Law on Loan Amounting to Public Cheating and Fraud

2. Competition Act

3. Commercial Banking Act

4. Law on the Finance Business Securities Business and Credit Finance Business

5. Chain Loan Control Act

6. Foreign Exchange Control Act

7. Law on Government Procurement Fraud

8. Act for the Protection of Layout-Designs of Integrated Circuits

9. Consumer Protection Act

10. Trademark Act

11. Currency Act

12. Tax and Duty Compensation of Exported Goods Produced in the Kingdom Act

13. Interest on Loan by the Financial Institution Act

14. Bank of Thailand Act

15. Public Company Act

16. Anti Money Laundering Act

17. The Industrial Product Standard Act

18. Copyright Act

19. Board of Investment Commission Act

20. Enhancement and Conservation of National Environmental Quality Act

21. Patent Act

22. Security and Exchange Commission Act

23. Revenue Code

24. Customs Law

25. Excise Law

26. Liquor Act

27. Tobacco Act

28. Foreign Business Act

29. Casualty Insurance Act

30. Life Insurance Act

31. Law on Agricultural Futures Trading

32. Computer Crime Act

33. Land Law

34. Forest Law

35. National Park Act

36. National Reserved Forest Act

37. Wildlife Preservation and Protection Act


Special Units


If the crime has occurred outside of Thailand, then the matter is handed to the office of the Attorney General who will then appoint a prosecutor to look at the matter. This is very common with transnational crimes which occur inside as well as outside of Thailand.

The investigation into a criminal act in Thailand can commence at any point in time and the alleged offender does not need to be present at the time of the investigation. Once the person who is being investigated is arrested certain documents and information will be required. You can see the other pages on arrest, bail as well as the criminal procedure in Thailand.

This only serves to show which investigators in Thailand will be used if you have committed a criminal act in Thailand. For most who visit Thailand, the local police investigator will be the one doing the arrest, or if you have overstayed your visa then the Department of Immigration will take over the investigation. Should it be a transnational crime then DSI or the Department for Special Investigation will take over.

Always speak to an attorney when arrested while in Thailand. A good criminal attorney will be able to assist you in understanding the Thai legal system as well as ensuring a good solid defense.


The information contained on our website is for general information purposes only and does not constitute legal advice.