A 21-year-old Scunthorpe man has been arrested on suspicion of causing serious injury through dangerous driving following a collision on the A18 near Gunness.
Officers investigating the collision between a blue Audi A3 and two cyclists are now appealing for witnesses to come forward.
All three were travelling westbound, towards Gunness Village
One of the cyclists, a 42-year-old local man, was taken to Hull Royal Infirmary with life threatening injuries, where he remains in a stable condition.
The second cyclist was also taken to Hull Royal Infirmary, where he was treated for minor injuries. The driver of the Audi was uninjured.
The 21-year-old arrested in connection with the incident has been released on police bail to a date next month.
Anyone who saw the collision, or any of those involved prior to the incident, is asked to call 101, quoting log number 653 of August 10.