(1)

No order issued under this section may authorise or approve the interception of any wire, electronic or oral communication for any period longer than is necessary to achieve the objective of the authorisation, nor in any event longer than sixty days and such sixty days period shall begin on the day immediately preceding the day on which the investigating officer first begins to conduct an interception under the order or ten days after order is issued whichever is earlier.

(2)

The extension of an order may be granted, but only upon an application for an extension made in accordance with sub-section (1) of section 38 and the Competent Authority making the findings required by sub-section (1) of section 39, and the period of such extension shall be no longer than the Competent Authority deems necessary to achieve the purposes for which it was granted and in no event for longer than sixty days at a time.

(3)

Every order and extension thereof shall contain a provision that the authorisation to intercept shall be executed as soon as practicable and shall be conducted in such manner as to minimise the interception of communications not otherwise subject to interception under this section and shall terminate upon attainment of the authorised objective, or in any event on the expiry of the period of said order or extension thereof.