Officers were called to the A48 Pwllmeyric, Chepstow at around 5.55am on Tuesday 7 July following a report of a road traffic collision involving an electric bicycle and a bus.
The cyclist was taken to hospital in a life-threatening condition and sadly died on Saturday 11 July in hospital.
His family has been informed, and specialist officers continue to support them.
As part of the investigation, officers are particularly keen to speak with anyone who witnessed the cyclist prior to the collision.
Investigators would like to hear from anyone who saw the cyclist travelling in the area before the collision, including motorists, pedestrians, cyclists, or anyone who may have captured relevant footage on a dashcam, CCTV system, mobile phone, or other recording device.
Anyone with information that could assist the investigation is asked to contact Gwent Police quoting reference 2600215220.
