Worker critical after fall at cross-river rail site

Police say the man fell between six and 10 metres from scaffolding before hitting a number of obstacles and then landing on a concrete building surface.

Authorities used a crane and cage to safely move the man after the fall.

"It's obviously very distressing for all these workers and especially his family," Inspector Andrew Tracey told reporters.

"Queensland police are assisting workplace health and safety currently at the scene and workplace health and safety will follow their procedures and investigate the circumstances around the fall."

The site has been shut down with workplace health and safety, police and union representatives on scene.