The seriously hurt man was rushed to hospital.
Police said the exact circumstances of the fall were unknown and an investigation was ongoing.
The number of people injured and needing hospital treatment for scooter accidents is on the rise.
The Royal Melbourne Hospital said e-scooter crash admissions rose from 29 in 2020 to 76 in 2021.
In 2022 so far, a total of 129 riders have been admitted, with 16 treated for major injuries.
E-Scooter trial operator, Neuron, claims Melbourne’s is one of the safest programs it has run.
Under the law, E-scooter riders can only use bicycle lanes, shared paths and low-speed roads.