The company was charged with scheme to defraud, conspiracy, criminal tax fraud and falsifying business records.
Special Counsel Jack Smith obtained grand jury subpoenas last month for communications between Trump, his campaign, and top campaign staffers and local officials in Arizona, Wisconsin, Michigan and Pennsylvania.
TPM has reviewed a subpoena issued to the Milwaukee County Clerk, dated Nov. 22.
The subpoenas went to at least five counties in swing states where the Trump campaign sought to reverse the election results in 2020.
They are Dane County, Wisconsin, Maricopa County, Arizona, and Wayne County, Michigan, the Washington Post reported. TPM confirmed Tuesday that another subpoena was sent to officials in Allegheny County, Pennsylvania, and received a copy of the subpoena issued to Milwaukee County.