A 17-year-old boy and a 36-year-old woman have been arrested on suspicion of conspiracy to commit murder after two men were injured in a crash involving an e-bike and a car.
Dorset Police said the crash, in Bournemouth, happened near the Cherford Road junction of Kinson Road, on Thursday at about 13:10 BST.
The car, a blue Mercedes, failed to stop at the scene.
The men, aged in their 20s and both believed to have been on the e-bike, were taken to hospital, one with life-changing injuries, the other with less serious injuries.
The arrested teenager and woman remain in custody, along with a 37-year-old woman arrested on suspicion of assisting an offender. All three are from Bournemouth, police said.
Det Insp Ian Allen said: "The incident is believed to involve people who are known to each other and is the subject of a detailed investigation by detectives.
"Anyone who saw the manner of driving or riding, of either the car or the bike in the moments before or after the collision, I would ask you to please contact us."
The force also wants to hear from drivers with dashcam footage and residents with doorbell or CCTV footage to come forward.
