The Centre has allowed the deputation of officers of the Indian Revenue Service (Customs and Central Excise) in the NIA to help the investigators probe the multi-layered trade transactions, they said.
The federal agency to probe terrorism-related cases had in December registered a case to look into the barter trade at the Line of Control (LoC) through Salamabad in north Kashmir's Baramulla district and Chakan-Da-Bagh in the Poonch district of Jammu region.
The IRS officials would also extend help in the money trail and in unearthing alleged 'benami' property and transactions made by some separatists groups in the Valley, the officials, speaking on the condition of anonymity, said.
The finance ministry recently allowed an IRS officer to join the NIA for an initial period of four months to look into various cross-border trade related cases being probed by the agency, they said.
It is expected that a few more tax officials may join the agency, the officials said.
The IRS officers' expertise lies in detecting service tax, central excise (which are now subsumed in the Goods and Services Tax) and custom duty evasion. Two key intelligence agencies of the finance ministry -- the Directorate of Revenue Intelligence and Directorate General of Goods and Services Tax Intelligence -- are manned by these officers.
The NIA claimed it has got crucial leads from the analysis of voluminous trade-related documents seized by it in raids conducted recently in connection with this case.
There is a case of over- and under-invoicing in which almonds are brought in for Rs 600-650 per kg as against Rs 250-300 per kg. The huge margin in the trade is suspected to have been exploited by terrorists, the officials said.
According to the cross-LoC trade agreement between India and Pakistan, products grown in both sides of Kashmir will be exchanged under the barter system. The products included 'badam giri' (almond) grown in parts of Pakistan-occupied-Kashmir (PoK).
As many as 21 items are listed for trading between both the countries, they said.
The trade of clothes, 'dupatta' (stole) and herbs is also under the scanner of the NIA for allegedly financing terror activities in the state, the officials said.
Traders from PoK were sending and receiving California almonds and it is alleged that the money was used for funding of terror groups in the state.
The NIA had earlier said in a statement that reliable information was received that a large scale transfer of funds from Pakistan to India has been taking place through the import of California almonds via the cross-LoC trade mechanism. "This is in gross violation of the state policy of prohibition on trade in 'third-party origin goods' through this mechanism and information indicated that these funds are being used for fomenting terrorism and separatism in the state of Jammu and Kashmir," it had said.