PORTLAND, Maine (AP)   The former owner of a Portland, Maine, market has admitted to charges using his store to defraud the federal government.

Prosecutors say 40-year-old Ali Ratib Daham conspired to defraud the government of about $1.4 million between 2011 and 2016. Assistant U.S. Attorney Jim Chapman says the case is one of the largest welfare fraud cases he’s ever prosecuted.

As part of an agreement, Daham pleaded guilty to three counts Tuesday and agreed to forfeit approximately $80,000 in seized cash and to pay full restitution.

Daham’s attorney declined to comment until after sentencing, which is scheduled for spring 2018.

He faces up to 20 years in prison.

Authorities say a joint investigation by federal and state officials revealed Daham and his brother regularly allowed customers to exchange public assistance for cash.