The allegations against Amazon were made in a documentary aired Thursday by German public broadcaster ARD, EUobserver reported.
The film stated that workers, who are brought in from all over Europe, have to work 15 consecutive days, are forced to live in camped houses and are paid less than what they were promised before leaving their home countries for Germany.
They are also constantly watched by security guards with shaved heads and dressed in neo-Nazi fashion, the documentary said.
"They go into the house when the people are not there. And also when they are there, sleeping or in the shower," said Silvina, a Spanish art teacher, who works at Amazon to support her husband and three children in Spain.
In response to the allegations made in the film, Amazon said it is investigating the situations at its seven distribution centers in Germany.
"Although the security firm was not contracted by Amazon we are, of course, currently examining the allegations concerning the behavior of security guards and will take the appropriate measures immediately," Amazon said in a statement after the documentary aired. "We do not tolerate discrimination or intimidation."