Breaking News

Donald Trump Jr.'s wife was exposed to an unidentified white powder after opening a letter intended for her husband ... TMZ has learned.

Law enforcement sources tell us Vanessa Trump was exposed to the substance Monday morning. The letter was sent to her mother's apartment in Midtown Manhattan. 

We're told Vanessa and 2 other people were taken to a hospital as a precaution. The substance itself was tested and NYPD says it's non hazardous. The envelope was reportedly addressed to Trump Jr., although it went to his mother-in-law's home.

We still don't know who sent it, or if there was an actual letter. The Secret Service is also investigating the matter.