The collision, which involved a white Renault Trafic van and a blue electric bicycle, occurred on Daedalus Way at its junction with Peak Lane at around 10.30pm on Wednesday.
The cyclist, a 56-year-old man from Fareham, suffered serious injuries.
A police spokesperson said: “Officers are making enquiries as to the exact circumstances of the collision and are keen to speak with anyone who can assist.
“If you were in the area at the time of the incident, or saw either the van or bike in the lead-up to the collision, then please get in touch.
“We are particularly keen to hear from anyone who has dash cam footage of the incident.
“Alternatively, you can call 101.”