MUMBAI, July 18 -- What appeared to be a routine transit operation at Mumbai airport turned out to be part of an organised international gold-smuggling network involving airport insiders and foreign carriers, investigators say. The Directorate of Revenue Intelligence (DRI) has seized 5.1 kg of smuggled gold worth Rs.7.49 crore and arrested six people, including three airport staffers and three Filipino transit passengers, in a late-night operation at the Chhatrapati Shivaji Maharaj International Airport. The intelligence-led operation was carried out on the intervening night of Wednesday and Thursday after DRI officers received specific information about a syndicate allegedly routing gold through Mumbai from Dubai in the United Arab Emirates and Bangkok in Thailand. According to DRI officials, the investigation revealed that the three airport staffers allegedly played a crucial role in helping the syndicate remove the smuggled gold from the airport premises after it was brought into India by transit passengers. The operation began with DRI officers intercepting two airport staffers who were allegedly attempting to take the smuggled gold out of the airport. During questioning, investigators identified and intercepted a third staffer, who was allegedly responsible for receiving the consignments from transit passengers inside the airport. The probe subsequently led officers to three Filipino transit passengers, who were arrested for allegedly smuggling the gold into India on behalf of the syndicate. In all, the DRI seized 5.1 kg of gold valued at Rs.7.49 crore and arrested six accused believed to be part of the organised smuggling network. "The operation resulted in the arrest of six persons involved in the organised smuggling of gold into India through the network," a DRI official said....