New Delhi, Nov 7 : The National Investigation Agency (NIA) on Tuesday said that it carried out searches at eight locations in Punjab, Uttarakhand, and Uttar Pradesh in a heroin seizure case. An NIA spokesperson here said that the agency sleuths carried out searches at the residences and offices of individuals involved in this case. Searches conducted on Tuesday have proven to be highly productive, resulting in the recovery of significant incriminating materials, including documents and digital devices, the official said. The case pertains to the seizure of a substantial quantity of narcotics, specifically heroin, which was intercepted upon its arrival in India through the Integrated Check Post (ICP) in Attari, Amritsar, on April 24, 2022. The contraband was concealed within a consignment of licorice roots (Mulethi) originating from overseas suppliers in Afghanistan. The case was initially registered by the Customs Officials at the Integrated Check Post (ICP) in Attari, Amritsar. The NIA took over the probe on July 30 last year with the objective of investigating not only the drug seizure but also the role of multiple companies and individuals involved in the drug racket and the related 'proceeds of illegal drug trade'. After the completion of its initial investigations, the NIA filed a comprehensive charge sheet against four suspects on December 16 last year against Razi Haider Zaidi, Shahid Ahmed aka Qazi Abdul Wadood, Nazir Ahmad Qani, an Afghan national and Vipin Mittal. /IANS