Three owners and operators of an Atlanta pharmacy were sentenced to several years in federal prison for illegally purchasing food vouchers intended for low-income families and fraudulently seeking reimbursement from the government, federal authorities said Friday.

Siblings Pauline Mediko Badiki, 56, and Ferdinand Mediko, 58, were sentenced to four years and six months in prison, according to a statement from U.S. Attorney Byung J. “BJay” Pak’s office.

Almost a year ago, they were convicted of conspiracy and 12 counts each of wire fraud, theft of government funds and defrauding the U.S. Department of Agriculture’s Special Supplemental Nutrition Program for Women, Infants and Children, known as the WIC program.

Ferdinand Mediko’s wife, Monica, 53, worked as a pharmacy technician at the business and was also convicted in the scheme. She was sentenced to three years in prison.

“The defendants abused a program intended to assist those most in need and diverted public funds to satisfy their own greed,” Pak said in a statement. “Vendors who buy WIC vouchers abuse the trust placed in them to serve pregnant woman and young children, and they will be shut down and prosecuted.”

The siblings owned and operated Poly-Plex Pharmacy, located in the Bankhead area of Atlanta, Pak’s office said. In 2005, the business became an authorized vendor of the WIC program, which provides food to low-income pregnant women and children up to age five in the form of paper vouchers, which can be exchanged for foods listed on the voucher.

Between 2009 and June 2013, the Badiki and the Medikos purchased WIC vouchers from low-income mothers for a fraction of their value instead of providing the infant formula and food listed on the vouchers, federal officials said. They then deposited the funds into their bank accounts as if they provided WIC recipients with the foods listed on the vouchers, and were reimbursed by the USDA.

Prosecutors said the trio deposited “tens of thousands” of WIC vouchers, resulting in about $6.5 million in federal reimbursements. That far surpassed the redemptions from large grocery stores in the area that also offered the program. More than $4 million of the reimbursements were fraudulent, Pak’s office said.

All three defendants must also serve two years of probation and pay $3,700; they will also have to pay restitution, but that amount has not yet been determined.