Donald Trump
Donald TrumpReuters

The US Secret Service on Thursday launched an investigation of presumptive Republican presidential nominee Donald Trump's former butler, after he called to kill US President Barack Obama on Wednesday.

The statements by Anthony Senecal, 84, who worked as Trump's butler for nearly 30 years and remains at his Mar-a-Lago estate in Palm Beach, Florida, were revealed by the site Mother Jones on Thursday. Senecal himself confirmed to the site that he had made the comments in a Facebook post.

On Thursday the Secret Service announced it was "aware of this matter and will conduct the appropriate investigation."

Senecal's post read: "To all my friends on FB, just a short note to you on our pus headed "president" !!!! This character who I refer to as zero (0) should have been taken out by our military and shot as an enemy agent in his first term !!!!! Instead he still remains in office doing every thing he can to gut the America we all know and love !!!!!"

Calling to vote for Trump to "put an end to the corruption in government," the butler added, "I cannot believe that a common murder is even allowed to run (killery clinton) OR that a commie like bernie is a also allowed to also run !!!!"

Trump's campaign quickly "disavowed" the post, with his spokesperson Hope Hicks saying in a statement that Senecal "is not employed by Mr Trump, and hasn't been since June of 2009. We strongly condemn these horrible comments from Mr Senecal."

CNN contacted Senecal on Thursday, and he confirmed he wrote the post but said instead of calling to shoot Obama, "I think I said hung."

"Either way, I don't care. Hanging, shooting - I'd prefer he'd be hung from the portico of the White House, or as I call it, the white mosque," Senecal said.

Senecal has been employed at Mar-a-Lago since around 1959, back when it was still owned by Marjorie Merriweather Post. Trump bought the property in 1985, and Senecal remained on staff. Seven years later he became Trump's butler.

Back in 2009, Senecal told Trump he wanted to retire, but Trump convinced him to stay as the in-house historian at Mar-a-Lago in an unofficial and unpaid post, although Senecal says he makes money leading tours at the luxurious estate.

Trump's butler took a few years off from the estate back in 1990 to be the mayor of Martinsburg, West Virginia.