Extended limitation not available where the department already knew of the activity and declaration had been filed.

Extended limitation could not be invoked where the assessee had already filed the required declaration and the activity was within Revenue's knowledge. The show-cause notice was issued beyond the normal period by relying on the extended period, but the prior declaration and departmental awareness removed any basis for alleging suppression or similar grounds. On those facts, the demand was held barred by limitation.

---

---

Issues: Whether the demand was barred by limitation and the extended period could be invoked when the relevant activity was already within the department's knowledge.

Analysis: The show-cause notice was issued by invoking the extended period of limitation. The respondent had filed a declaration in May 1987, and the department had required the requisite declaration under the exemption notification. On these facts, the activity was already within the knowledge of the Revenue, and there was no justification for issuing the notice beyond the normal period.

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

---