A letter that was meant to be sent to the White House on March 17, Tuesday, was said to be positive for cyanide after it was tested at an off-site mail screening facility, the US Secret Service said in a statement, according to New York Times.
According to the e-mail sent by Secret Service spokesman Robert Hoback, the envelope arrived at the White House mail screening facility on March 16, Monday, USA Today reported.
It was tested initially for any biological agents; the result came up negative. However, officials said after the subsequent tests that the letter appeared "presumptive positive" for cyanide on Tuesday. In lieu to this, the letter was sent to another facility to be tested further for final confirmation.
The U.S. Secret Service did not indicate whether the letter was for President Obama or someone else in the White House. Moreover, they confirmed that nobody in the White House was hurt due to the exposure to the envelope.
Hoback said in the statement that they will have no additional comment to the incident as it is an ongoing investigation.
Weeks before the 9/11 attack, a stack of letters laced with anthrax was sent to a number of the members of news media and public officials in the Washington area-this includes the White House and members of the Congress. There were five recorded deaths due to exposure to the substance and 17 others were sickened. Because of this occurrence, the officials blamed a medical scientist who eventually committed suicide.
As a result of the threats and panics, it has been ordered by the authorities that the letters and packages intended to be sent to the White House be screened and tested thoroughly at remote locations for the protection of the president and his staff.
Cyanide is a toxic chemical compound that when exposed, the individual's body will not be able to make use of oxygen and might lead to death if not treated immediately.