The US Secret Service has launched an internal investigation into a member of Vice President JD Vance's security detail over allegations related to a suspected leak of sensitive information, the agency said Thursday.

Secret Service spokesperson Anthony Guglielmi said the employee is under internal review and could also face a criminal investigation over allegations involving compromised "operational and information security."

"While we will not comment on the specifics of this matter, one principle is unequivocal: any conduct that potentially threatens the safety of a protectee will not be tolerated," Guglielmi said in a statement.

The agency did not identify the individual under investigation.

According to the Secret Service, the inquiry stems from a report published last week by MS NOW, which said some agents assigned to Vance's protective detail had privately expressed frustration over last-minute travel requests involving the vice president and his family.

Vance's office declined to comment and referred inquiries to the Secret Service.

Vice President Vance and his wife, Usha, reside at the official vice presidential residence at the US Naval Observatory in Washington with their children.

The couple welcomed their fourth child, Alec Neel Vance, on Sunday. According to the vice president's office, he is the first child born to a sitting US vice president in more than 150 years. The couple's other children are Ewan, 9, Vivek, 6, and Mirabel, 4.