Officers were called at around 5.30pm on Friday 8 September 2023, to a collision involving a grey Vauxhall Corsa and a white and blue Suzuki motorbike.
The incident is said to have taken place on the Londonbound carriageway between the Whitfield roundabout and the junction for Lydden.
The rider of the bike, a man in his 30s, was pronounced deceased at the scene.
Officers from the Serious Collision Investigation Unit (SCIU) are carrying out enquiries and would like to hear from anyone who might have witnessed the collision.
They are also appealing for anyone with dashcam or CCTV footage taken in the area around the time to come forward.
Witnesses should call the SCIU appeal line on 01622 798538 quoting reference AH/DH/098/23. You can also email sciu.td@kent.pnn.police.uk
Footage can be submitted here: https://kep.uk.evidence.com/axon/community-request/public/a2whitffield