Bus passengers are taking free rides in Shenzhen using fake money, according to Xinhua. Shenzhen Bus Corp, which runs the city's public bus services, has collected more than 50 million yuan in fake money - mostly one-yuan bills - tendered for fares over the past two years. Since 2003, most of the city's 100 bus routes have been operated without ticket collectors and some patrons have taken advantage. According to Xinhua, the bus company collects about 40,000 yuan worth of fake bills every day. In the first four months of this year, the amount collected in counterfeit bills has reached 2.5 per cent of the public bus operator's turnover. Local banks have expressed concern and warned Shenzhen Bus Corp that they might have to review their business relationship if the company cannot guarantee the 'integrity' of its revenue. One local bank, with which the company has lodged about 40 million yuan in deposits, has complained that at least 3 per cent are fake. The company has begun installing counterfeit bill detectors in all of its buses. The bus company said the detectors had an accuracy rate of 95 per cent and was hopeful the new machines would be able to stem the losses.