The package was found Saturday evening in a next-door neighbor's driveway in Bel Air, the Los Angeles Police Department told the Los Angeles Times and KNBC television, the NBC affiliate in Los Angeles. The package also included a Christmas card with negative comments about President Donald Trump and the new US tax law signed by Trump last week
An LAPD bomb squad X-rayed the package before opening it and found the horse manure inside, police told local media. Aerial footage from KNBC showed officers investigating a large box in wrapping paper, then dumping a large amount of what they later identified as the manure and opening the card that was included inside.
Mnuchin, who KNBC said was not home when the package was discovered, is a former Goldman Sachs Group Inc executive and Hollywood film financier.
A road in Bel Air was closed for about two hours, KNBC reported.The US Secret Service is also investigating the incident, according to the TV station.