Outgoing Sen. Carl Levin's Saginaw office was evacuated yesterday after receiving a suspicious letter.
The FBI now says the letter tested negative for ricin.
The staffer had contacted authorities and the office was evacuated.
The Saginaw Fire Department, Saginaw HAZMAT and Saginaw police first responded to the scene at 515 North Washington.
Later the FBI took over the investigation.
This scare came as Sen. Roger Wicker of Mississippi and President Barak Obama were each mailed letters containing the deadly poison ricin.
Two MMR medics and one Levin staffer were initially hospitalized during the incident, but all three have now been released, according to MMR.
Sen. Levin's office has also released a statement regarding the issue.
??I have been advised by the FBI that preliminary testing by the Michigan Department of Community Health, Micro-Biology Laboratory in Lansing showed negative results in the suspicious letter received by my Saginaw office. The office is open as usual this morning. I want to express my appreciation to the local, state and federal authorities who responded to this incident so quickly and professionally.??
Watch NBC25 at 6 with Bill Harris tonight for more on this story.