Can a state legislate to extend the period of preventive detention beyond three months without the advisory board's opinion?
Yes, a state can legislate to extend the period of preventive detention beyond three months without the advisory board's opinion. The relevant clause (4) states that "No law providing for preventive detention shall authorise the detention of a person for a longer period than three months unless… an Advisory Board has reported before the expiration of the said period of three months that there is in its opinion sufficient cause for such detention." This indicates that while the advisory board's opinion is required for detention beyond three months, the law itself can extend this period.