(Reuters) – Dollar Tree Inc (NASDAQ:) Tuesday’s subpoena by the Eastern District of Arkansas to the federal grand jury was issued in connection with a pest- and sanitation-related problem. This comes a month after U.S. regulators discovered a contamination problem at Family Dollar division.

Recently, a Family Dollar distribution centre in Arkansas was contaminated with Salmonella by rodents. This led to the recall of human, animal, and cosmetic drugs from six U.S. States including Alabama, Arkansas, Louisiana and Louisiana.

Dollar Tree earlier this month stated that the recall had caused it to take a $34.1million hit.

According to the U.S. Food and Drug Administration, rodent contamination can cause Salmonella and other infectious diseases. This could pose a greatest risk for infants, children and pregnant women as well as the elderly and people with immunocompromised.

Also, the FDA stated that conditions discovered during an inspection of the facility contained both live and decayed rodents.

Dollar Tree also revealed that it had been bitten by more than 2300 rodents from March 29 to Sept. 17 according to its records.

Dollar Tree filed a regulatory document on Tuesday showing that the Eastern District of Arkansas asked for information and documents pertaining to pests and sanitation.

A grand jury subpoena can be used by the federal government as an investigative tool to uncover and obtain evidence concerning a federal crime.

Dollar Tree filed that it stated, “We are committed to fully cooperating with the subpoena, and any associated investigation. However, we cannot guarantee the timing of the matter or its outcome.”