Donald Trump's Sister, Like His Son, Received Threatening Letter

The latest to receive a threat mail in the Donald Trump family is his elder sister, Maryanne Trump Barry. She got a threatening letter on Friday, which put the entire family on tenterhooks, said law-enforcement sources.

The 78-year-old judge got a hostile mail at her Manhattan, Philadelphia house. The note was similar to the mail received by Trump's 32-year-old son, Eric. There was a "suspicious white powder" enclosed in a letter, and a threat that if the front-runner did not back out, his family would get harmed.

Maryanne Trump Barry, a judge with the U.S. Circuit Court of Appeals for the 3rd Circuit, had come in the hit list earlier this year. Trump mentioned her as a joke, when he was asked who he would appoint to the U.S. Supreme Court. GOP rival Ted Cruz called her a "radical pro-abortion extremist" as she ruled against banning abortions in New Jersey.

When Eric's wife, Lara, opened his letter at his Trump Parc East home, the cops called the white substance "non-hazardous".

"Multiple Trump relatives have been told to be mindful of the mail threats and what they are opening," another federal law-enforcement source said. "Anything suspicious, they immediately call authorities."

He is the sole GOP candidate who has Secret Service protection. While Democratic candidates Hillary Clinton and Bernie Sanders have security details, the Ohio Gov. John Kasich and Sen. Ted Cruz do not have those details, according to a spokesman for the Secret Service.

Both the FBI and Secret Service are investigating the mysterious incident.

"The FBI is aware of the incident and is working closely with the United States Secret Service and U.S. Marshals Service," the FBI Philadelphia said. It did not come out with more facts or details.

There was no immediate response from Donald Trump's representatives.