Authorities investigate threatening letter sent to Donald Trump's son

A hazmat team reported to former United States president Donald Trump's eldest son, Donald Trump Jr's home in Jupiter, Florida after he received and opened a letter containing an unidentified white powder and a death threat, the Daily Beast reported.

"The test results of the substance came up inconclusive on what it was exactly, but officials on the scene do not believe it is deadly," a spokesperson for Trump Jr said in a statement to ABC News.

While the Jupiter Police Department has not yet commented on the incident, it marked the second known incident where the younger Trump has received an envelope containing a suspicious white powder.

During his father's presidency in 2018, Trump Jr's then-wife Vanessa opened an envelope addressed to him and was rushed to the hospital as a precaution.

Following the incident, a man from Massachusetts was arrested and sentenced to five years of probation in connection to sending numerous threatening letters containing suspicious powder to multiple high-profile individuals, including Trump.

Preliminary tests showed the substance was not dangerous, the police said at the time.

Donald Trump Jr has been campaigning alongside his father, speaking at events in Iowa, New Hampshire, and South Carolina.

He is also set to attend a fundraiser for his father in Washington, DC, next month, alongside Trump's Congress allies including House Speaker Mike Johnson and Sens. Steve Daines, Tim Scott and JD Vance.