(3) For the purposes of clause (5) of Article 22 of the Constitution, the communication to a person detained in pursuance of a detention order of the grounds on which the order has been made shall be made as soon as may be after the detention, but ordinarily not later than five days, and in exceptional circumstances and for reasons to be recorded in writing, not later than fifteen days, from the date of detention. 10. Cases in which and circumstances under which persons may be detained for periods longer than three months without obtaining the opinion of Advisory Board. —(1) Notwithstanding anything contained in this Act, any person (including a foreigner) in respect of whom an order of detention is made under this Act at any time before the 31st day of July, 1999, may be detained without obtaining, in accordance with the provisions of sub-clause (a) of clause (4) of article 22 of the Constitution, the opinion of an Advisory Board for a period longer than three months but not exceeding six months from the date of his detention, where the order of detention has been made against such person with a view to preventing him from engaging in traffic in narcotic drugs and psychotropic substances, and the Central Government or any officer of the Central Government, not below the rank of an Additional Secretary to that Government, specially empowered for the purposes of this section by that