Officers are continuing to appeal for information following a serious fail to stop collision in Widnes.
At 12.27pm on Saturday 11 September a report was received of a collision involving a mobility scooter and a blue Piaggio Beverly moped on Lower House Lane, Widnes.
The rider of the mobility scooter, an 88-year-old local man, has been taken to hospital with serious injuries.
The moped failed to stop along with a fluorescent yellow quad bike.
A 26-year-old man from Runcorn and a 20-year-old woman from Widnes were arrested on suspicion of failing to stop following a collision, causing serious injury by dangerous driving and drug driving.
A 31-year-old man and a 27-year-old man, both from Widnes, were also arrested on suspicion of causing serious injury by dangerous driving and for failing to stop after a collision.
The 26-year-old, 20-year-old and 31-year-old have since been released under investigation.
The 27-year-old man remains in custody being questioned by detectives.
Anyone with information is asked to contact Cheshire Police on 101 quoting IML 1082550 or report it via the Cheshire Police website.
Information can be passed on to Crimestoppers anonymously by calling 0800 555 111 or report it via the Crimestoppers website.