A 600-metre pipe used to pump industrial oil to a plant where it was made into dutiable diesel oil and then stored in an underground tank was unearthed by Customs in Lau Fau Shan yesterday. The pipe weaved through bushes in remote Sha Kiu Sheung Village and the manufacturing plant was built inside an abandoned pig pen midway along the tube. 'One end of the tube was used to pump raw material [industrial oil] into the manufacturing plant about 100 metres away,' head of Customs' Diesel Oil Enforcement Division Law Man-wai said. 'After completing manufacturing work, tax-free diesel oil was then pumped into the underground tank through a 500-metre long tube. 'Trucks would come to collect the illicit oil and deliver it to illegal oil stations.' Customs officers arrested a 38-year-old man and a 34-year-old mainlander.