Kaitlin, 28, from the US, is suspended from hooks pierced through her skin by professional body artist Dino Helvida in Zagreb, Croatia on June 7. Photo: CFP

On the rooftop of an empty building in Zagreb, Dino Helvida carefully pierces his client Kaitlin's torso, legs and face before putting hooks through her skin.

Shortly after, he suspends her from a metallic frame, her heavily tattooed body dangling horizontally in the air.

Helvida, 27, is a professional piercer and body suspension expert from Bosnia Herzegovina, who for the last six years has been hanging up the bodies of those brave enough to partake in what is an extreme form of body piercing, sometimes for hours.

The process is carefully done, and in this case Helvida works with his girlfriend Zorana. It involves first piercing the skin with needles, putting through metallic hooks, which are then attached to a thin rope to lift the suspended off the ground.

"It is painful. Piercing is painful, it's just like regular piercing," Helvida said. "Every time it's a new piercing and the wound heals really fast, it can heal in two weeks. I had hooks in my forehead and nobody can tell I had them."

How long a person remains suspended varies, depending on their position and how they feel. "Some people stay for four, five hours, some people need only three seconds," he said.