Police are appealing for witnesses and dashcam footage of a serious collision in Cheltenham last week.
The incident happened shortly before 5.40pm on Wednesday 10 July on the Arle Court roundabout near the junction with the Golden Valley.
It involved two vehicles, a grey Volkswagen T-Cross and a red Honda CBR650 motorcycle.
On initial attendance a motorcyclist, a man aged in his 70s, was found to have sustained a leg injury and he was taken to hospital.
His health has since deteriorated and he is in a serious condition at Southmead Hospital.
Anyone who witnessed the collision or who has dashcam footage and has not already spoken to police can provide this information online by completing the following form and quoting incident 368 of 10 July: https://www.gloucestershire.police.uk/tua/tell-us-about/cor/tell-us-about-existing-case-report/