He was punched several times in the face, possibly with a knuckle duster, after his car was forced to stop in Mason Street, Blakenhall, at around 11pm on December 27.

Its path was blocked by a van and a man is thought to have thrown himself on the bonnet of the officer's car to prevent it from moving. The officer was then attacked by a second man.

Colleagues reached the scene at the same time as another car drew up in the road. This vehicle tried to drive away after spotting the police but was stopped and a samurai sword and knuckle duster were allegedly found.

A 42-year-old man has been arrested and charged with assaulting the off-duty policeman. Two other people have been interviewed in connection with the alleged discovery of the samurai sword and knuckle duster.

West Midlands Police confirmed that they were investigating the incident. The injured man received a fractured nose in the attack.