An investigation by the city's Ombudsman has found it is common for rental bike service operators to leave their bicycles where they block paths, saying the situation "invites doubts" as to whether the Leisure and Cultural Services Department (LCSD) has taken action against offenders.

The Office of the Ombudsman on Thursday said business permits issued by the department to the operators explicitly forbid them from allowing rental bicycles to take up space outside designated areas.

"Operators placing their bicycles outside the permit area in violation of regulations not only causes an obstruction to passageways and affects members of the public to access and use recreational facilities, but may also pose safety hazards," said Ombudsman Jack Chan.

"Our multiple site inspections found that it seems to be a common practice for operators to leave bicycles lying around in contravention of the regulations, and this has invited doubts as to whether the LCSD had reminded the operators of the irregularities or has taken enforcement action against them in the past."

The office noted that LCSD staff issue reminders or warning letters depending on the severity of a situation, and can consider suspending an operator's business or terminating the contract if there's no evident improvement after a third warning.

But guidelines do not clearly stipulate the number of verbal and written reminders to warrant a warning, the office said, or whether the notices have any validity period.

The office said the department should take "decisive enforcement action" if any operator violates the contract terms, and look into enhancing the current enforcement regime and guidelines, among other suggestions.

The Ombudsman added that the LCSD has accepted all of its recommendations.