A suspicious letter sent to the office of a Mississippi senator Tuesday tested positive for a deadly poison, The Wall Street Journal said.
The letter was addressed to Senator Roger Wicker's office, but was intercepted before reaching Capitol Hill, ABC News and The Wall Street Journal said. The letter had no return address but was postmarked from Memphis, Tenn., said ABC News.
After the letter was screened at a senate mail facility in Maryland, it was flagged for possibly containing poison, The Wall Street Journal said. The preliminary test for ricin came back positive, ABC News said.
A spokesperson for the Capitol Police told The Wall Street Journal that the envelope contained a "white granular substance." Mail to the senate has been suspended, ABC News said.
The substance was sent to the lab and final results will be available within 24 to 48 hours, The Wall Street Journal said.
Authorities told ABC News and The Wall Street Journal an individual who frequently sends letters to members of Congress is being questioned.