Authorities say they arrested 17 people, including four apparent ringleaders, last week.
Officials believe the group worked with criminals from Russia, Turkey and Ukraine, to help migrants enter Poland with visas based on fake employment documentation.
“Criminals, with the help of fictitious business entities (including temporary employment agencies), issued fictitious statements for migrants that allowed them to take up employment,” Polish police said in a release.
“After arriving in Poland, foreigners never took up employment in accordance with the statements or applications, but left for Western Europe.”
The group, operating since 2012, earned more than €2.3 million (US$2.5 million) for their work.
Europol, who assisted with the investigation, says the majority of the illegal migrants came from Eastern Europe, Africa and Asia.
It's the second time this month that Polish criminals have been linked to human smuggling.
In early November, Croatian police arrested two Polish citizens they suspected in a scheme to smuggle migrants inside a wooden crate hidden in a Volkswagen van.
The European Commission has pinpointed Poland as a “transit country” for illegal migrants.
“Women and children from Eastern Europe, particularly Bulgaria, Romania, and Ukraine, are subjected to sex trafficking in Poland. A growing number of Vietnamese victims transit Poland en route to Western Europe after being subjected to labour trafficking in Russia,” reads a report from the commission.
The report notes that Polish police - including its border guards - have been subjected to better training to help combat migrant smuggling and exploitation in recent years.
