Traffic police in the southern Chinese city of Shenzhen have reportedly arrested a cyclist they say knocked down a woman at a bus stop, and they have criticized the bicycle-sharing company whose bike the suspect was allegedly riding for faulty brakes and not releasing information that would help the investigation.

The sharing bike police say the suspect used. /Photo from Shenzhen Traffic Police

According to a report in Shanghai news portal The Paper on Friday, a 29-year-old woman identified by police as Gao struck an older woman with her ofo bike on May 27 and then fled the scene on another ofo bike. The victim sustained a fractured rib in the collision on Shennan Road.

The 29-year-old suspect is tracked via surveillance camera. /Photo from Shenzhen Traffic Police

Shenzhen traffic cops immediately contacted ofo for help identifying and tracing the renter of the two bicycles, but the company refused to offer any information and initially denied that any of its bikes had been involved in the incident, the police force said on its Weibo account on Tuesday.

Screenshot of the first announcement by Shenzhen traffic police on the case. /Photo from Shenzhen Traffic Police

Ofo bikes and those of other dock-less bicycle-sharing schemes are wildly popular in China. Users must register for a phone app that lets them obtain codes to unlock the bikes. They are supposed to lock them again at the end of each ride to close the hire period and leave the bike ready for another user.

However, bike-sharing companies have been criticized for the fallibility of the locking system – in some instances the passwords can be easily deciphered if users forget to formally end their trip, leaving uncertainty as to the bikes’ real riders. In a statement, ofo said the suspect in the May 27 incident may have unlocked the bike in “an irregular way.”

Declaration released by ofo on the case. /Photo from Shenzhen Traffic Police

Shi Shaochen, public relations CEO at ofo, told The Paper that the company was replacing its password combination padlocks with electric locks to improve security and the accuracy of data gathering.

It has also published user codes aiming to educate cyclists on the right way to lock and unlock the bikes.

The electric lock on an ofo bike. /VCG Photo

The Shenzhen traffic police remain unsatisfied though. They released another Weibo statement on Saturday saying the accident was at least partly caused by brake failure. And the police again pressed ofo to provide detailed user information on the bicycles involved in the case.

Screenshot of another announcement released by Shenzhen traffic police. /Photo from Shenzhen Traffic Police

Earlier this year, ofo settled out of court for an undisclosed amount with a user who sued the company over an alleged brake issue that he said caused him to fall off his bike.

Dock-less sharing bikes at a Beijing subway station. /VCG Photo

There are likely to be more of these kinds of cases now that bike sharing has once again earned China the nickname of the “the Bicycle Kingdom.” According to a report by Research and Markets, there were 20 million bike-sharing users in the country in 2016 and the number is projected to reach 198 million by 2021. In the capital city, Beijing, there were 700,000 sharing bikes crowding the streets as of April.