The suspect, 43, was arrested in a Berlin raid following an investigation launched in June last year. Police said she had been on authorities' watch-list from previous trafficking cases, AP reported.

Besides the aforementioned woman, another 25-year-old Vietnamese and a 64-year-old German are also being probed for allegedly trafficking foreigners and enforcing prostitution.

Police and prosecutors said the 43-year-old woman allegedly made her victims work in nail studios or massage parlors. All three are accused of profiting from 10 people staying in Germany illegally, who allegedly paid off debts to their smugglers by working for the 43-year-old woman.

They are also being accused of illegally securing residency in Germany for the immigrants through sham marriages and forging paternity acknowledgements.