An envelope containing what appeared to be the deadly poison ricin was sent to President Trump, but never made it to The White House, a report said Tuesday.

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

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

“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.

The FBI said that the substance was undergoing further testing.

Ricin is a highly toxic compound extracted from castor beans. Tiny doses of the compound can be deadly if swallowed, inhaled or injected.