The family had smuggled 50 women into Spain since 2016, took their passports, then forced them to care for the elderly in private homes and confiscated most of the money they made, Spain's Civil Guard said, the AFP reported Thursday.
"The criminal group dominated and controlled all of its victims with constant threats, intimidation, deceptions and coercion, warning them that their relatives in Nicaragua would suffer the consequences if they reported what was happening," police said in a press release Wednesday.
The family-run gang, which included two sisters, reportedly made about €750,000, or $840,000, through the scheme.
The seven family members were arrested and charged with human trafficking to exploit labor, money laundering and being in a criminal organization, the AFP said.
Gang members' relatives would recruit women back in Nicaragua, and they specifically would target "mainly young women with little education," police said.
Four women and three men were arrested, including a 48-year-old woman who was arrested at the Madrid airport while accompanying three "victims from Nicaragua who were going to be exploited".
According to Spanish police, the gang members would promise the women a good job in Spain, but when they arrived claimed the women owed them €6,000, or about $6,700, and that it must be paid back quickly.
The gang had found elderly clients by placing ads online, the police said. Not only were the women forced to give up most of their earnings, but the gang also made money off the women by charging them inflated prices for basic items.