The smuggling ring is accused of forging EU citizenship documents and placing the workers with large logistics companies.
German police have conducted dozens of raids in a nationwide investigation against alleged human smuggling.
The searches focused on 20 suspects accused of illegally bringing temporary workers into Germany from outside the European Union.
Police and customers officers raided a number of homes and businesses across the country as part of the investigation.
Federal police in Berlin said on Twitter that the operation started at 07:00 on Wednesday, led by the general prosecutor's office.
Homes and businesses in the German capital and the surrounding Brandenburg state were searched, as well as premises in Bremen and Lower Saxony. An estimated 1,000 police officers were involved in the raids, according to the DPA news agency.
Several arrest warrants were issued and millions of euros in assets were also seized on Wednesday.
The smuggling ring is accused of forging EU citizenship documents and placing the workers with large logistics companies. The group allegedly operated a network of temporary employment agencies in the Balkans, according to federal police.
The ring is also accused of forging documents to register the workers as EU citizens before placing them in large German logistics companies.
Investigations are being conducted on suspected charges of trafficking foreigners, forgery of documents, organised illicit work, and illegal employment.
“It is incredibly perfidious to want to make money from people’s hardship, to shamelessly exploit their helplessness and desire for a better life,” Berlin’s police union said in a statement, according to DPA.