An internal investigation has been launched after police raided a Birmingham pub to check for drunk customers.

Twelve officers swept through the The Prince of Wales pub in Moseley, carrying out sobriety tests on punters.

Drinkers were made to walk along a straight line chalked on to the pavement at the rear of the pub and officers told bar staff that customers were intoxicated and out of control, landlord Keith Marsden said.

But Mr Marsden insisted it was a normal Friday evening, branding the police "bully boys". He said: "I'm absolutely outraged. It's complete nonsense and if it wasn't so serious it would be a joke.

"Why are police officers wasting taxpayers money investigating whether or not people are drunk in a pub? It's unbelievable."

Mr Marsden, 43, has lodged a formal complaint about the visit in October last year, and West Midlands Police confirmed it was investigating the matter.

A force spokesman said: "West Midlands Police received a formal complaint in November which is being investigated by our Professional Standards Department. It would therefore be inappropriate for us to comment further at this stage."