The piece of mail sent to Trump appeared to be connected to two other letters which were sent to the Pentagon, according to reports.

A Secret Service spokesperson confirmed the receipt of a suspicious envelope addressed to the president on Oct 1.

“The envelope was not received at the White House, nor did it ever enter the White House,” the spokesman said.

Earlier on Tuesday it was revealed that two envelopes addressed to Secretary of Defense James Mattis and Chief of Naval Operations Adm. John Richardson initially tested positive for ricin at the Pentagon’s mail facility.

The Pentagon packages, which were delivered Monday, were intercepted before making it into the headquarters of the Defense Department, spokesman Chris Sherwood said.

Ricin is deadly when inhaled or injected into the body.

Quotes from CNN are used in the update