Agra: The Archaeological Survey of India (ASI) here has registered a police case for a suspected security breach after a helicopter made four unannounced sorties over Taj Mahal-- a protected heritage monument.

The incident took place on December 14 when ASI officials and CISF security personnel deployed to guard the 17th century monument spotted a helicopter flying above it and the chopper repeated its sorties for three more times.

"We have lodged a complaint with the local police regarding the incident which is a breach of security of the monument. We have been told that a television crew onboard the helicopter had taken permission from the Union Home Ministry and Civil Aviation ministry for taking shots of the monument but we were not informed about it," ASI Conservator Munazzar Ali said.

Sources said the helicopter was spotted four times-- 0935-0945 hours, 1500-1510 hours, 1625-1630 hours and the last one at 1720 hours, sending the Central Industrial Security Force (CISF) personnel into tizzy on December 14.

Both the ASI and CISF have informed their headquarters in Delhi and the agencies are now trying to check how the lack of communication did happened and the units in Taj Mahal were not informed about the air exercise.

Sources said personnel of a private firm were onboard the private helicopter to shoot a promotional campaign of the heritage monument.

"Taj Mahal is a protected monument by the ASI. The Supreme Court has ruled that there can be no unauthorized activity including photography and videography in the 500-metres vicinity of the monument and hence as a stipulated measure we have informed the police," Ali said.