Small shops, barbershops and steam shops are suspected to be frontlines for illegal activities such as human trafficking and money laundering as part of a National Criminal Agency (NCA) investigation known as operation machinery.
The Shrewsbury raid was located in a barber shop in the town centre, one of five nearby, which was also targeted by surgery.
West Mercia police arrested one man for money laundering crimes in connection with the attack on a barber shop in Worcester, while three others were arrested in Hereford and Worcester for immigration crimes.
Det Insp Fenn said police saw many barber shops open across the country, both urban and rural.
“That's not to say that all of them are running illegally, but obviously more and more pop-ups are asking questions,” he said.
He said that the attacks were found to be organized crime, but police had to act quickly as the criminals progressed.