Police are urging witnesses to come forward following a serious crash on Charles Purley Way near Shripney.
Officers were called by ambulance crews shortly after 12 midnight on Thursday (18 June) to a report of a red Kia car and a cyclist colliding.
The cyclist – a 17-year-old boy – suffered serious injuries and was taken to hospital where he remains in a critical condition.
Officers located the Kia nearby and a 21-year-old local man was arrested on suspicion of failing to stop at the scene of a collision. He has been taken to custody for questioning.
Road closures were in place but have since been lifted.
Police would like to speak to anyone who may have witnessed the collision or who may have seen the cyclist or vehicle beforehand.
Anyone with information can report online or call 101 quoting Operation Newtown or serial 6 of 18/06