The tanker, filled with 12,000 litres of kerosene from Bharat Petroleum corporation, on Saturday was seized when it was being taken to a Kosi Kalan-based factory, with the connivance of wholesale dealer, Kotwali police station Inspector Sanjai Jaiswal said.
They also mixed some chemicals to the kerosene to change its color to prevent it getting identified, he said.
Some chemical was mixed in kerosene to turn it into a red colour liquid so that it could not be identified, Jaiswal said.
An FIR has been filed in the matter on the complaint of Supply Inspector Preeti Singh, Jaiswal said.
Efforts are on to identify the owner of the factory, he said.
Meanwhile, District Supply Officer K P Mishra said, "The license of the wholesale dealer andthe purchasing factory have been cancelled by District Magistrate.