Beijing's transportation watchdog has threatened to revoke the business licenses of retailers found selling electric bikes that break the government-set speed and weight restrictions.
High-speed and oversized e-bikes have become a "severe threat" to public safety, according to a Beijing Daily report that cited sources with the capital's Transport Commission.
China has banned e-bikes that can travel over 25 kilometers per hour, while the maximum designed weight allowed is 55 kilograms.
However, many of the 4 million e-bikes on Beijing's roads are above the acceptable standards, the authority said.
To tackle the problem, the capital — which has about 1,000 e-bike retailers — is to introduce tough measures to punish rule breakers.
Starting July 1, those found selling oversized bikes or helping customers to illegally modify vehicles will be stripped of their business license.
Substandard bikes and malfunctioning charging units can also cause fires, the city fire department was cited as saying in the report.