Armed man shared lift with Obama

US President Barack Obama makes a toast during a luncheon hosted by UN Secretary-General Ban Ki-moon at the UN General Assembly in New York September 24, 2014. Photo: Reuters

President Barack Obama rode in a lift with an armed security contractor who had assault convictions, in what appears to be another security lapse.

It happened on 16 September when Obama visited the Centers for Disease Control and Prevention in Atlanta.

The incident came to light on Tuesday, hours after the boss of the Secret Service was grilled by Congress about a security breach at the White House.

A Secret Service official confirmed the incident but declined to comment.

The gun was found when the man was questioned after taking a video in the lift and was immediately fired by his employers, according to newspaper reports.

The Washington Post said the man had three convictions for assault and battery.

"This person was within arm's length of the president with a gun," said Utah congressman Jason Chaffetz, who was told of the incident by a whistleblower.

It will come as another embarrassment on the day when the director of the US Secret Service, Julia Pierson, took responsibility before a hostile House oversight committee hearing for an "unacceptable" security breach at the presidential residence.

Omar Gonzalez, 42, scaled a fence at the White House, ran across the lawn, entered an unlocked door, entered the East Room and was eventually tackled inside.