The FBI has taken Kevin Paul Curtis of Mississippi into custody, in suspected connection with the letters sent to President Obama and Senator Roger Wicker and a Mississippi justice official that were laced with the deadly poison ricin.

Curtis claimed he had unearthed a conspiracy of human body part sales on the black market, and believed "various parties within the government" were attempting to damage his reputation, according to Reuters.

Curtis, 45, was arrested Wednesday at his Corinth, Mississippi home.

According to a statement released by the Justice Department, Curtis is "believed to be responsible for the mailings of the three letters sent through the U.S. Postal Inspection Service which contained a granular substance that preliminarily tested positive for ricin."

Ricin is a poison that comes from castor beans. It is highly toxic, and is most harmful when inhaled. It seeps into the body's cells and prevents the cells from producing necessary proteins.

The letters were received following the Boston Marathon explosions, which set citizens across the nation on edge.

The ricin scare merely added fat to the fire, despite the fact that the FBI maintains the two incidents were unrelated.

The envelopes, addressed to President Obama and Senator Wicker, bore identical diction. Each read, "To see a wrong and not expose it, is to become a silent partner to its continuance," and were signed, "I am KC and I approve this message."

Both had postmarks from Memphis, Tennessee and were dated April 8.

Not much is known about the enigmatic Curtis. He had been living in Corinth, a small city of almost 14,000 citizens, located in northeastern Mississippi since December. He has no record with the law, and police have never had contact with him prior to his arrest, the Corinth Police Department told the Associated Press Thursday. Curtis apparently lived in government housing as well-a single-story home with red brick and white trim.

Upon his arrest, police kept watch around Curtis' home. The FBI were to search his house later that morning.

Senator Wicker released a statement after Curtis' arrest, thanking the FBI and police "for their professionalism and decisive action in keeping our family and staff safe from harm."