Letter with ricin poison sent to White House may have come from Canada: RCMP

The RCMP said Saturday it is working with the FBI after federal U.S. officials intercepted an envelope addressed to the White House that contained the poison ricin.

"The RCMP can confirm that it has received a request for assistance from the FBI in connection with a suspicious letter sent to the White House," spokesperson Dan Brien told CBC News in an email.

"Initial information from the investigation suggests that the letter originated in Canada," said Brien. He said he could not offer more details at this time.

A spokesperson for Public Safety Minister Bill Blair said his department was aware of the reports.

The letter was intercepted at a government facility that screens mail addressed to the White House and U.S. President Donald Trump, an official told The Associated Press. A preliminary investigation indicated it tested positive for ricin, a poison found naturally in castor beans, the official said.

The official was not authorized to discuss the ongoing investigation publicly and spoke on condition of anonymity.

The FBI, the Secret Service and the U.S. Postal Inspection Service were leading the investigation.

In a statement, the FBI said agents were working to investigate "a suspicious letter received at a U.S. government mail facility" and that there is "no known threat to public safety."

WATCH | Letter containing toxic substance mailed to White House: