Officers from the Roads Policing Unit are appealing for witnesses to a serious road traffic collision in Old Swan on Sunday, 6 December.
At around 10.15pm, emergency services were called to Prescot Road near to the junction with St Oswald's Street following a road traffic collision involving a scooter and a taxi.
The 17-year-old rider of the scooter, who has suffered serious head injuries, has been taken to hospital.
The driver of the taxi stopped at the scene and is assisting officers.
Witness and CCTV enquiries remain ongoing. Prescot Road between St Oswald's Street and Queens Drive was closed while examinations were carried out at the scene.
Inspector Beth Blake said: "We are keen to speak to anyone who saw the incident, or any drivers in the area who may have dashcam footage. Any footage or information could be vital in establishing what happened."
You can call the Roads Policing team on 0151 777 5747, or contact them via Twitter @MerPolCC or Facebook ‘Merseyside Police Contact Centre’, with reference 973 of 6 December.