Officers were dispatched to Gillingham Dam shortly after 4.15pm after receiving reports of a collision involving a black SMC quad bike and a grey Peugeot 2008.
Emergency personnel, including an air ambulance, were dispatched to the scene. The collision caused serious injuries to the driver of the quad bike, a man in his 60s. He was taken to the James Paget Hospital for treatment, where he is still being treated.
The collision caused no injuries to the driver of the Peugeot, a woman in her forties.
Loddon Road, The Street, Bridge Street, and Gillingham Dam have all been closed. They reopened shortly before 6.30 p.m.
Police are asking anyone who witnessed the collision or the driving style of either vehicle prior to the incident to come forward.
Please call 101 or email PC Andrew Lincoln in the Wymondham Roads and Armed Policing Team, quoting incident 268 from yesterday (22 June 2022).