CORINTH, Mississippi — A man accused of mailing letters with suspected ricin to national leaders believed he had uncovered a conspiracy to sell human body parts on the black market and claimed “various parties within the government” were trying to ruin his reputation. Paul Kevin Curtis, 45, was arrested Wednesday at his home in Corinth, near the Tennessee state line. Authorities were waiting for definitive tests on intercepted letters that were addressed to President Barack Obama and Republican Sen. Roger Wicker. Preliminary field tests can often show false positives for ricin. Ricin is derived from the castor plant that makes castor oil. There is no antidote and it's deadliest when inhaled. An FBI intelligence bulletin obtained by The Associated Press said the two letters were postmarked Memphis, Tennessee. Both letters said: “To see a wrong and not expose it, is to become a silent partner to its continuance.” Both were signed, “I am KC and I approve this message.” It was not immediately known what charges Curtis faced. In Corinth, a city of about 14,000, police cordoned off part of a subdivision where Curtis lived. At least five police cars were on the scene. Neighbors, who said Curtis kept to himself and did not seem violent, were concerned by the idea that someone was making poison in the house that sits so close to their bedrooms and front yards. Multiple online posts on various websites under the name Kevin Curtis refer to the conspiracy he claimed to uncover when working at a local hospital from 1998 to 2000. The author wrote the conspiracy that began when he “discovered a refrigerator full of dismembered body parts & organs wrapped in plastic in the morgue of the largest non-metropolitan healthcare organization in the United States of America.” Curtis wrote that he was trying to “expose various parties within the government, FBI, police departments” for what he believed was “a conspiracy to ruin my reputation in the community as well as an ongoing effort to break down the foundation I worked more than 20 years to build in the country music scene.” In one post, Curtis said he sent letters to Wicker and other politicians. “I never heard a word from anyone. I even ran into Roger Wicker several different times while performing at special banquets and fundraisers in northeast, Mississippi but he seemed very nervous while speaking with me and would make a fast exit to the door when I engaged in conversation...” He signed off: “This is Kevin Curtis & I approve this message.”— AP