White House
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A suspect who allegedly sent a letter containing the deadly poison ricin to the White House was detained trying to enter the United States from Canada, a federal law enforcement official said Sunday, according to NBC News.

Additional information about the person was not immediately available. The suspect was detained by Customs and Border Protection agents, a federal law enforcement official said.

The FBI said on Saturday that it was investigating a suspicious letter addressed to President Donald Trump that had been intercepted.

It was not clear when the letter was sent or where it was intercepted. Law enforcement officials said the poison, which is highly toxic and can cause nausea, vomiting, organ failure and death, was detected at an off-site facility that screens mail addressed to the White House.

The ricin was confirmed in field and laboratory tests.

In 2018, a man was arrested in Utah in an investigation into envelopes filled with ricin that were mailed to Pentagon officials and to President Trump.

The envelope sent to Trump appeared to be connected to similar envelopes sent to the Pentagon.