The introduction of rubber into Malaysia in the early 20th century resulted in the opening of big estates by the British and Singaporean cultivators. Up till 1916, six estates covering an area of 15,000 acres (61 km²) were opened in the Mukim of Plentong. In 1916, Kampung Pasir Gudang became the centre for Police, Customs and opium-control besides being a centre for the 'penghulu' of the Mukim of Pasir Gudang. The formation of estates had also resulted in influx of labourers from China and India.