Anthrax hoax letter sent to Arizona Sheriff Joe Arpaio's office

An explosives unit was recently dispatched to the downtown Phoenix offices of controversial Arizona Sheriff Joe Arpaio after the discovery of a suspicious envelope containing a white powdery substance.

Arpaio said the envelope was delivered to his home over the weekend and he took it to his office with him on Monday morning. The sheriff said that he was immediately suspicious of the envelope because it was addressed to the White House and had his home address listed as the return address, according to Fox News.

Arpaio said he has never sent anything to the White House.

"Resign or die. Sincerely, Joe Arpaio," the letter inside the envelope stated, Fox News reports. Arpaio told reporters the letter concluded, "Here's some anthrax for you."

The 19th floor of the Sheriff's office was immediately evacuated, but the Phoenix Fire Department said that they were almost certain the material inside was not harmful.

The Secret Service announced that they were aware of the incident and that an investigation has commenced. The envelope is not believed to have been delivered to the White House at any point.

The embattled sheriff was recently at the center of a controversy with the federal government. His Maricopa County jail officers were recently barred from checking the immigration status of inmates after the release of a critical Justice Department investigation.