Republican U.S. Rep. Marilyn Musgrave‘s re-election campaign was already heated, and it just got smelly as well: Her staff accused a Democratic activist Thursday of leaving an envelope full of dog feces at Musgrave’s Greeley office.

Musgrave spokeswoman Shaun Kenney said someone stuffed the envelope through the mail slot in the door on May 31 and then sped away in a car. Kenney said most of the preprinted return address was blacked out, but staffers used the nine-digit ZIP code to trace it to Kathleen Ensz, a Weld County Democratic volunteer.

Ensz told The Associated Press she left the envelope at Musgrave’s office but said it “wasn’t in the office doors, it was in the foyer.” Asked what she meant by the act, she declined comment.

Kenney demanded an apology from Musgrave’s likely Democratic opponent, state Rep. Angela Paccione of Fort Collins.

Paccione spokesman James Thompson denied the campaign had anything to do with it.

So many questions about such an important story…. Why would someone include their nine-digit zip on a package containing such a thing? Doesn’t something stink about this?