The presumption of innocence is a fundamental right in Indian criminal law, enshrined in Article 20(3) of the Constitution. However, as an exception, preventive detention laws like the National Security Act (NSA) and the Unlawful Activities (Prevention) Act (UAPA) allow for detention without trial, effectively reversing the burden of proof.

These laws are justified on the grounds of national security and public order, as they aim to prevent individuals from engaging in activities that may threaten the state. The Supreme Court has upheld the constitutionality of preventive detention laws, provided they adhere to the procedural safeguards laid down in Article 22 of the Constitution.Laws like the Prevention of Money Laundering Act (PMLA) have also been criticized for shifting the burden of proof onto the accused. While the government argues that these laws are necessary to combat serious crimes, civil liberties advocates contend that they undermine the presumption of innocence and due process.

The increasing use of such laws raises concerns about the erosion of fundamental rights and the creation of a new norm where the exception becomes the rule. It is crucial to strike a balance between national security and individual rights, ensuring that preventive detention laws are used judiciously and in accordance with constitutional principles.