According to reports, the man hopped over a security barricade -- called a "bike rack" -- set up between the sidewalk on Pennsylvania Ave and the White House Fence. The man was allegedly carrying a document which he wanted to deliver to the President and did not have any weapons on him.

A CNN report says the man was arrested within two minutes of jumping the fence and the vehicle he arrived in is currently being searched.

TMZ broke the story ... a man who arrested on White House grounds last week was turned away by Secret Service agents just hours before he successfully gained entry for 20 minutes.