The off-site mail facility for the capitol intercepted a letter today that contained ricin, a deadly poison made from the castor oil plant.

Federal authorities stated on Tuesday that the letter, addressed to Republican Senator Roger Wicker, never made it to his desk.

The letter was tested on three occasions and tested positive in all three instances.The letter has since been sent to the Federal Bureau of Investigation’s laboratory in Quantico, Virginia for further testing.

The letter was postmarked in Memphis, Tennessee but had no return address, suspicious markings or any other identifiable information with it. But according to Senator Clair McCaskill, the Democratic Senator from Missouri, the letter was sent by someone who frequently writes to the lawmakers. That person, although not revealed, has been identified.

The senate mail facility will remain closed for two to three days as law enforcement continues their investigation according to the Senate Sgt at Arms Terrance Gainer.

The state offices of Senators has been warned to be on the lookout for other letters that may contain the deadly substance.

It was in the aftermath of the September 11th attacks that Anthrax-laced mail appeared in newsrooms and congressional offices. That attack killed five people.

Currently, there is no indication that these latest attacks are related to the bombings that took place in Boston yesterday.