A MAN has drowned and a woman narrowly escaped with her life from an underground tunnel beneath Brisbane’s CBD after they were trapped by rising water.

In shock and exhausted from performing CPR, the woman raised the alarm at the Eagle St Pier after thunderstorms dumped heavy rain across the city just after 4pm.

The pair were kayaking on the Brisbane River when they entered an underground tunnel to explore beneath the city.

media_camera Police search the river at Eagle St Pier where the woman raised the alarm. Pic: Steve Pohlner

They became trapped when a sudden storm hit, dumping more than 60mm of rain and causing localised floods almost a metre deep in parts of the city.

QPS Regional Duty Officer Inspector Sean Cryer said: “She managed to get to a place of safety for about an hour until the water has subsided. When she’s come out she has found her partner in distress. She has provided CPR and then she’s exited the tunnel to get help.”

Police said the tunnel entrance was initially submerged and inaccessible when they arrived on scene.

media_camera Police carry out a search on the Brisbane River near the Eagle Street Pier. Picture: Steve Pohlner

Rescue crews recovered the man’s body just after 6pm near Riparian Plaza.

The Sunday Mail has unearthed a website devoted to “underground exploring” across Brisbane with photos and videos revealing hundreds of metres of tunnels beneath the city streets.

A message on one video has pictures of a woman kayaking and says: “Storm drain exploration is extremely dangerous please do not try it! You could die!”