A motorcyclist remains seriously injured in hospital after he came off his bike in a crash on a dual carriageway.

Police are investigating a collision involving a black and white Yamaha bike and a silver Ford Mondeo on the A405 in Watford on Saturday.

It happened at the junction with Greenwood Drive at around 12.40pm.

Emergency services were dispatched to the scene, including an air ambulance, which landed behind Woodside Leisure Park.

Watford Observer:

The road was closed in both directions until 3pm.

The motorcyclist, aged in his 30s, was taken to St Mary's hospital in London for treatment.

Police say he has sustained multiple fractures to his arms, legs, and ribs, and he remains in hospital.

Officers are appealing for witnesses to the crash which happened in the middle of the A405 in an area where drivers can turn in and out of Greenwood Drive.

At this stage, police are unsure how the crash occured which is why the force is appealing for help.

Police have confirmed the driver of the Mondeo, a man in his 40s, was arrested on suspicion of drug driving.

He has been released under investigation while enquiries continue.

PC Matt Holliday, from the Bedfordshire, Cambridgeshire and Hertfordshire Road Policing Unit, said: “I am appealing for anyone who saw the collision, or the events leading up to it, to get in touch.

"Similarly, if you have information about the incident or think you might have captured it on dash cam please let us know as it could help us to progress the investigation.

“If you can help, please email me at matt.holliday@herts.pnn.police.uk quoting ISR 255 of 4 April.”