Federal agents raided homes in Orange County, Los Angeles County and San Bernardino County in an effort to investigate the practice of maternity tourism. An apartment complex near John Wayne Airport was one of the locations where search warrants were seized and documents and computers taken.

Law enforcement officials interviewed several pregnant women who paid tens of thousands of dollars to companies touting American citizenship, free education and other benefits of having their children born in the United States and thus, being American citizens. Most of those interviewed and investigated where Chinese.

The women were promised Social Security numbers and United States passports for their newborn babies when they returned to their native country. Many of the women were allegedly paying up to $50,000 to the operators of these companies.

Law enforcement authorities estimate the couple who operated You Win USA Vacation Resort in Irvine made $2 million in 2013 and helped women give birth to 400 children in Orange County, according to affidavits released Tuesday by U.S. Immigration and Customs Enforcement.

It is not illegal for foreign nationals to give birth in the United States.

In order to curb the practice of pregnancy tourism, authorities are looking into visa and tax fraud, money laundering and conspiracy. Many of the women interviewed allegedly were told to hide their pregnancy at airports and avoid questions about why they were traveling to the United States in an attempt to conceal their real purpose.

You Win USA Vacation Resort, USA Happy Baby Inc. and Star Baby Care are the main companies law enforcement is focusing on pursuant to their warrants.