A driver for Didi – China's homegrown Uber competitor – was caught half naked while working on Monday in north China's Tianjin City, triggering public concern over the safety and supervision of online car-hailing services.

Public concern over the safety and supervision of online car-hailing services has increased after Didi, China's homegrown Uber-competitor, was involved in another sex scandal.

The driver has been detained for 10 days for being half naked yesterday when servicing a female passenger who hailed his car through Didi application, local police said.

The woman, going by the name "Dandan Noodles 0228," posted her experience on microblogging website Sina Weibo. She claimed that she hailed a car through Didi's app on Monday morning. Halfway through the ride, she realized that the driver was wearing nothing from the waist down. He only had a pair of short pants loosely over his private parts.

The woman took a photo of the driver secretly and got off as soon as she could. She then contacted Didi's customer service and provided the photo as evidence. However, she only got a 10-yuan (US$1.53) coupon in compensation.

Later on Monday, the woman wrote on her blog again, claiming she was threatened by the driver and showing a screenshot of the threat.

In response to the scandal, Didi's spokesperson said that the company hadn't got in touch with the driver yet, but based on the evidence provided by the passenger, the company had halted his service. When the evidence is verified, the spokesperson went on, the driver will be banned for good.

The spokesperson also said that the company would launch an in-app police number to further enhance protection.

The government has also acted to regulate ride-hailing services. Local authorities in major cities like Shenzhen, Guangzhou, Hangzhou and Shanghai have taken measures to overhaul the market. The Ministry of Transportation is likely to introduce a regulation proposal later this month.

China's ride-hailing services have been involved in a string of scandals recently. Earlier this month, a woman was suspected of being murdered by a Didi driver in south China's Shenzhen City. In March, Didi, Uber and other car-hailing services in Shenzhen were found to not be conducting necessary investigations into drivers' qualifications. Last July, a driver who registered on Didi with stolen information raped a female passenger in Beijing.