A Cleveland Police spokeswoman said the 22-year-old man arrested in connection with the incident has been released on bail.
The injured man remains in an induced coma in hospital, police confirmed.
Officers say they have been searching for all evidence from the scene. It is unclear whether they have found the missing penis.
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An 11-year-old boy has been airlifted to hospital after a collision with a 4x4 vehicle in Northumberland.
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