Extended limitation fails without wilful suppression, where approvals and returns were accepted and concealment was not proved.

Extended limitation could not be invoked absent proof of wilful suppression or deliberate misstatement, particularly where the assessees had obtained separate approvals, filed classification lists and RT-12 returns, and the department had accepted them without objection. Contemporaneous departmental approval and the department's own uncertainty on the exemption notification negated any inference of concealment. The duty demand raised beyond the normal period was therefore barred by limitation, and rejection of the extended-period basis was upheld.

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Issues: Whether the duty demand could be sustained by invoking the extended limitation period on the footing of wilful suppression or misrepresentation, and whether the demand was barred by time.

Analysis: The respondents had applied for and obtained separate base-clearance approvals for each unit from the Co-ordinating Assistant Collector, and the department had accepted the classification lists as well as the RT-12 returns without objection. The record showed that the departmental understanding of the exemption notification was itself uncertain, and the contemporaneous approvals and returns negatived any inference of deliberate concealment. In these circumstances, the ingredients necessary to invoke the extended period under Rule 10 were not established, and the demand raised beyond the normal period could not be sustained.

Conclusion: The demand was barred by limitation and the invocation of the extended period was not justified.

Final Conclusion: The appeal was rejected and the order setting aside the demand on limitation was upheld.

Ratio Decidendi: Mere availment of duty relief in a manner later disputed by the department does not justify the extended limitation period unless wilful suppression or deliberate misstatement is proved, especially where the department had contemporaneously approved the relevant declarations and returns.

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