Donald Trump's former butler has drawn the attention of Secret Service for threats online he's made against President Barack Obama.

Anthony Senecal, who served the presumptive Republican nominee at his Mar-a-Lago club in Florida, has a Facebook page filled with incendiary comments. Many of the posts are directed at the president and his family. The posts were first reported by Mother Jones.

In one message from September 2015, Senecal said the military should hang Obama for treason and other "high crimes." In another that month, he described Obama, a Christian, by using a slur for a member of the Muslim faith. In that post, he wrote that he does not speak for Trump: "This is my opinion, only!!!!"

Senecal declined to accept a reporter's call placed to the antiques dealer in West Palm Beach, Florida, where he works, but told Mother Jones he wrote the posts.

Trump's campaign, criticized in the past for the way it's reacted to the racist comments of some supporters, condemned the posts.

"Tony Senecal has not worked at Mar-a-Lago for years, but nevertheless we totally and completely disavow the horrible statements made by him regarding the president and first family," spokeswoman Hope Hicks said in a statement.

A recent profile of Senecal in The New York Times reported that after he tried to retire in 2009, Trump kept him on as an unofficial historian at Mar-a-Lago.

The Secret Service said Thursday it is "aware of this matter and will conduct the appropriate investigation." Such an investigation routinely involves a face-to-face interview with someone thought to have made threats against the president or another protected official.