Seven of the suspects have been placed in pre-trial detention after being formally charged, police spokeswoman Edyta Adamus said.
Investigators believe the group treated criminal activity as a steady source of income and invested proceeds in assets including real estate in Bulgaria.
According to police, the suspects recruited Bulgarian women with promises of agricultural work.
Once in Poland, the women's passports were confiscated and they were forced into prostitution.
Authorities said the group had also operated in the northwestern Polish city of Koszalin between 2019 and 2022, carrying out similar crimes.
The arrests were made during a coordinated operation involving Warsaw criminal police, investigative units and counter-terrorism officers, including raids in the town of Mińsk Mazowiecki east of the capital.
Prosecutors have charged eight of the suspects with participating in an organised criminal group involved in human trafficking, coercion into prostitution, robbery, extortion and drug distribution.
A court ordered three months’ pre-trial detention for six Bulgarian suspects, while a 36-year-old Polish woman was remanded for two months.
A 29-year-old Polish man and one Bulgarian suspect were released after initial proceedings, state news agency PAP reported.
(gs)
Source: IAR, PAP