After the Supreme Court’s judgment in Prabir Purkayastha v. State (2024), **failure to supply written grounds of arrest makes the arrest illegal**, and therefore:
\[
\boxed{The person cannot be validly remanded and must be released.}
\]
Why?
Under Article 22(1), the arrested person must be informed of the grounds of arrest.
The Court held that in UAPA — a statute with severe consequences — the communication must be in writing.
Without written grounds, the Magistrate cannot apply judicial mind to the legality of the arrest (a precondition for valid remand).
Any remand order based on an illegal arrest is itself unconstitutional.
Therefore:
\[
No written grounds → No valid arrest → No jurisdiction for remand.
\]
This rule now applies to all special laws where liberty is severely restricted (UAPA, PMLA, NDPS, etc.).