Zac Efron has explained how he came to land on top of an airport security guard earlier this week.

The High School Musical hottie had just arrived at LAX airport after a flight from New York when his attempts to evade the waiting paparazzi took a slap-stick turn.

As Zac ran up an escalator to escape, a security guard helping him tripped and fell and Zac fell on top of him.

The actor says, "There were so many paparazzi. It was crazy...When there’s that many paparazzi, you can’t see. People start yelling. People get hurt.

Going down? Zac and a security guard take a tumble

"While I was running, the guy in front of me kind of fell and then I fell on top of him.

“It was kind of weird. The guy was not a bodyguard - he was just a guy from the airport helping out. I felt terrible."

We suspect he felt even more terrible when he realised a photographer had captured his tumble on camera.