Customs duty on base oil and furnace oil is comparatively lower than diesel.
While importers have to pay Rs 20 per liter as customs duty for diesel, customs duty for base oil is only Rs 15 per liter.
Similarly, only five percent customs duty is levied on furnace oil.
Data of Biratnagar Customs Office shows 91 consignments of base oil and furnace oil entered the country during the blockade.
"Diesel imported in the name of base oil and furnace oil were sold at very high price in the market as the fuel was scarce due to the blockade," a source at the customs office told Republica. "They even issued tax invoice of base oil and furnace oil to consumers to evade income tax."
Base oil is used as raw material to produce lubricants. There are lubricant producers in Morang -- Fujima Oil Company and PLO Lubricant. Fujima Oil imported 219,960 kiloliters of base oil in five consignments during the blockade. PLO Lubricant, however, did not import base oil from the customs point during the blockade.
Customs records show Nepal Oil Corporation (NOC) as well as other trading companies imported 71 consignments of furnace oil during the blockade.
Sources say importers started to import diesel in the name of base oil and furnace oil after the government decided to allow private sector to import fuel.
These companies sold diesel to cement factories, telecom service providers and other businesses in Biratnagar, Bhairahawa, Pokhara and Dang.
"We don't have laboratory to test the quality and type of oil being imported," an officer at the Biratnagar Customs Office told Republica. "We levy customs duty as per the declaration made by the importer."
According to the customs office, base oil and furnish oil are imported from India, China, Singapore, USA and UAE, among others.
Data shows even defunct industries imported furnace oil and base oil during the blockade.
Koshi Petro Chemical of Morang imported 289.46 tons of furnace oil during the blockade even though it is closed since July last year.
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