But her spokeswoman told CNN that inside one letter received Thursday was a condom, removed from its original packaging.
McCollum's spokeswoman Maria Reppas said Thursday that the congresswoman's district office in St. Paul received the condom in an envelope dated March 23, along with an anonymous typed letter reading: "Betty McCollum you've been dry f***** by the liberal party."
The condom had been removed from its original packaging and placed in a plastic bag, according to McCollum's district director. McCollum's office said the U.S. Capitol Police and local law enforcement are investigating the package along with another one received Thursday.
Her office also reported receiving part of a shredded American flag doused in gasoline and a typed letter addressed to McCollum, Rep. Keith Ellison, Sen. Amy Klobuchar and Sen. Al Franken - all Democrats from Minnesota.
"Each of you receives part of a shredded American flag," the letter read. "It represents Obama and your liberal filth. Open the bag, it's covered in the stench you've brought to our government ... Because of you, we are now a country of dirt, shame, corruption and slime."
McCollum released a statement late Thursday responding to the threats.
"I will not back down in the face of attacks, threats, and violence," she said. "I do not regret my vote, and I will proudly stand in the face of opposition and defend my support of health care reform."