Former governor Tomas Yarrington told MVS radio station that President Felipe Calderon's administration was using the allegations to help the candidate of his conservative National Action Party, or PAN, which has sought to portray Yarrington's Institutional Revolutionary Party as corrupt and soft on drug trafficking.
"What is happening here is a malicious use of law enforcement instruments to influence an election once again," Yarrington told the radio station. "It is very clear that they are trying to make the investigations coincide with the campaign ads and political speeches of the PAN candidate."
U.S. authorities have filed civil suits to try to confiscate a condominium in South Padre Island and a 46-acre (18.6-hectare) property in San Antonio allegedly owned or controlled by Yarrington. He has denied owning the properties.
No criminal charges have been filed against Yarrington, who was Tamaulipas governor from 1999 to 2004.
"I have not had any relation with organized crime, I have not received bribes nor have I protected any criminal," he said. "I have not laundered money, nor do I have real estate interests in Texas."
Mexican investigators have ordered his accounts frozen, but Yarrington claimed he had only about 200,000 pesos ($11,500) in the accounts.
Yarrington also said he had no business dealings with a Mexican businessman, Fernando Alejandro Cano Martinez, named in a U.S. indictment.