A former employee of the Ascension Parish Health Unit has pleaded guilty to stealing more than 400 Social Security numbers from a state database and selling them to a Baton Rouge tax return preparer who used them to file bogus IRS returns, federal prosecutors said Wednesday.

Ta’Sha Thomas, 26, of Donaldsonville, admitted Monday in U.S. District Court in Baton Rouge to selling the numbers to Mona R. Hill in 2012 for $8,000 to $9,000, the U.S. Attorney’s Office said in a statement.

Thomas pleaded guilty Monday before Judge James J. Brady to single counts of trafficking in counterfeit devices and fraud with identification documents. Brady did not set a sentencing date.

Hill already has been sentenced to serve nearly 51/2 years in federal prison and ordered to pay $491,268.18 in restitution to the IRS.

At the time of Thomas’ employment in parish government, the parish operated health units in Donaldsonville and Gonzales, and administered contracts with the state Department of Health and Hospitals for various social welfare programs.

Federal prosecutors said Thomas, who worked as a clerk at the Health Unit in Donaldsonville, accessed the COMPASS database at the unit to gather the Social Security numbers. COMPASS is a state database used for the Special Supplemental Nutrition Program for Women, Infants, and Children — also known as WIC.

Thomas worked for the parish from June 2011 to September 2012 and had access to the Social Security numbers because she checked in people for WIC.

Kenny Matassa, Health Unit director, said parish officials received a call from the FBI about two years ago and he turned over requested information but suggested it is DHH that monitors the database, not the parish.

Lester Kenyon, parish government spokesman, said the parish-maintained computers at the Health Unit do not have access to Social Security numbers.

DHH officials were asked for comment late Wednesday but did not provide a response.

Hill admitted in July 2013 that her company, Mona’s Dependable Tax Service, filed 488 false tax returns totaling about $661,258 in claimed refunds. Hill admitted she received nearly $500,000 from the bogus returns.

Prosecutors said Wednesday the probe into the stolen Social Security numbers is ongoing and being conducted by the IRS’s Criminal Investigation Division.

Follow David J. Mitchell on Twitter, @NewsieDave.