A watchdog is investigating claims that a man was assaulted by a police officer as he was arrested in Leeds.
The 19-year-old man alleges he suffered a broken bone in his neck as a result of being hit by a baton on 29 August.
West Yorkshire Police referred the case to the Independent Police Complaints Commission who are investigating.
The man was arrested on suspicion of drinking and driving. He later pleaded guilty to that charge and assaulting a police officer.
The IPCC said the man was found to be injured when he was taken to the Weetwood custody suite in Leeds.
He had earlier been detained by police on the city's ring road.
He was taken to hospital where he was found to have a fracture in his neck.
IPCC commissioner Nicholas Long said: "It is appropriate that the IPCC independently investigate to determine how the man sustained his injury.
"If this was as the result of a baton strike then we will have to determine the justification for that use of force and the reason for the strike being delivered to the man's neck."