All deceased human bodies in the custody of the coroner must be held until such time as the coroner after consultation with the state‘s attorney, the police department of the city, the state highway patrol troopers on duty in that county, or the sheriff has reached a decision that it is not necessary to hold the body longer to enable the coroner to decide on a diagnosis, giving a reasonable and true cause of death, or that the body is no longer necessary to assist any one of those officials in their duties.