Gung Aji is dealing with a public relations crisis; sitting on a stool outside his tiny kiosk on a dusty track in Bunbungan village in Semarapura, a public-transport hub in southeast Bali, he is anxious to clear his name of accusations he sells dirty fuel. 'It was my assistant who was mixing the fuel and as soon as I found out about it, I fired him,' he said. 'I do not want to upset my customers, my livelihood depends on them.' Mr Aji (an alias) typically earns about 300,000 rupiah (HK$253) a month to support his wife and three children, of which 90,000 comes from selling petrol in two-litre bottles for motorbikes and other vehicles such as tractors. He does roaring business, as the nearest petrol station is 15km away. However, his fuel sales dropped recently as word spread that he was not selling pure petrol. 'After I bought petrol from his shop, my bike broke down and the mechanic said it was because of dirty fuel in the engine,' Wayan Degdeg said. He now travels 2km to the next village to buy fuel. Mixing fuel is common across Indonesia, where more than half of the population live below the poverty line as defined by the World Bank. 'Poverty and unemployment breed this situation, making people more vulnerable,' oil industry analyst Kurtubi said. 'And the government's differentiated pricing system and fuel subsidies create the opportunity for them to mix kerosene and diesel and sell the diluted product as pure diesel.' The mix ratio is usually 80 parts diesel to 20 parts kerosene, but sometimes it is as narrow as 60:40, enabling small traders selling around 10 litres of petrol a day to boost fuel profits more than 150 per cent. However, it is not just small traders that motorists must be wary of; petrol station owners have also been arrested for mixing fuels.