Family: A man died after the Charleston police officer signed a form refusing treatment.

JEFFREY COLLINS, Associated Press

The family of a South Carolina man who died a few days after a car accident, charged with driving under the influence of police, said that a police officer had signed a form refusing him medical treatment.

Family Lawyer Justin Bamberg said 58-year-old Nathaniel Rhodes had eight broken ribs and a deep cut in the liver. The delay in medical care led to his death four days later.

(MORE | SLED studies the handling of the Charleston DUI case after the suspect's death in police custody)

Bamberg showed a video Monday to Rhodes reporters at Charleston County Jail after his arrest on August 12. She shows paramedics joking as he slips in and out of consciousness and moans in pain. An officer asks him to sign a form but he does not answer.

Charleston police asked the State Law Enforcement Division to investigate Friday after NBC News asked questions about the case.