President Nestor Kirchner's administration is blamed for using incorrect inflation data to compute last month's consumer price report.
Mendoza Vice Gov. Juan Carlos Galiff said the province reported inflation of 3.1 percent for August to the federal government's National Statistics Institute, or INDEC, but the agency recorded that figure as just 1.5 percent in its official report.
INDEC did not immediately respond to the complaint.
For months, economists have said they suspect the federal government of manipulating data to make inflation appear lower than it really is in the runup to next month's presidential election.
The governor of Mendoza, Julio Cobos, is the running mate of Kirchner's wife, Cristina Fernandez de Kirchner, for the Oct. 28 vote.
Four years of robust recovery from a 2002 economic crisis have buoyed her in the polls, but challengers have seized on inflation to attack both Kirchners ever since the president imposed price controls in 2005 to keep inflation down.
Critics say inflation will actually hit 13 to 18 percent for the year, higher than INDEC's reported 8.7 percent.
Complaints first arose after the head of INDEC's consumer price index team was replaced in January by an official believed to close to Kirchner's government.