The incident is now being referred to the police's professional standards department.
The crash happened at around 4.40pm on Tuesday, when a Ford Fiesta, VW Polo and Ford Focus were involved in the collision on Greyhound Hill, Ketley Bank.
The Ford Focus was parked at the time of the crash.
The 45-year-old driver of the Fiesta suffered injuries and was taken to hospital following the collision. He was arrested at the scene but taken to hospital due to a suspected head injury.
Police remained with him to conduct road traffic procedures before he was later returned to his home address, having been released under investigation. In the early hours of Thursday, police were notified that he had died at home.
A statement from West Mercia Police said: "Due to police contact with the man in the days prior to his death the matter has been referred to our professional standards department as is normal procedure.
"If you witnessed the incident, have dash cam footage, or have any information that can help officers with their enquiries, you can report online on our website under the Tell us About section here, quoting incident number 437i of February 23, or you can call 101."