Officers also discovered a garage workshop in Dudley Port had been turned into a bar.
About 70 people have been fined after police disrupted an illegal nightclub in Birmingham over the weekend.
West Midlands Police said they had received information that part of a building on Buckingham Street had been turned into a bar.
After witnessing a number of taxis drop people off at the venue on Saturday night, officers forced their way inside to find 150 people packed into the building across two floors.
As well as the bar, with neon signs and a dance room, officers came across a recording studio and gym.
Some officers were pelted with bottles and one suffered a minor injury as a door was smashed open by people trying to break out.
Fifty people are believed to have fled when police arrived, but about 70 revellers were caught and issued with £200 fines. The DJ could also face a £10,000 fine.
Assistant chief constable Chris Todd said: “Our officers continue to work long and hard to protect the public and reduce the spread of this deadly virus by breaking up these gatherings, often in really difficult circumstances.
“It’s unacceptable that our officers came under attack, and that one suffered a minor injury, just for doing their job and enforcing laws that are in place to keep us all safe.
“While there’s much to be hopeful of in terms of the rollout of coronavirus vaccines, people must remember that we are still in lockdown and the virus is still a real threat to communities across the West Midlands.”