The 27 Romanians, held captive in two apartments in Faura, near Valencia, were released by police.
"The victims were recruited from Romania, with false promises of a job, and were later forced to work without pay and while being held captive," said a press release issued by the ministry.
"In addition, when they were out of work they were forced to beg," the document reads. "They were living crowded, in terrible conditions, in two apartments and they did not escape for fear of retaliation," according to the source.
The investigation was unfolded when two Romanians complained of having been held hostage in Alicante (southeastern Spain).