A huge fault in the Earth's crust near Los Angeles is leaking helium, researchers have found.

They say the unexpected find sheds new light on the Newport-Inglewood Fault Zone in the Los Angeles Basin.

It reveals the fault is far deeper than previously thought, and a quake would be far more devastating.

It follows a report from the U.S. Geological Survey has warned the risk of 'the big one' hitting California has increased dramatically.

UC Santa Barbara geologist Jim Boles found evidence of helium leakage from the Earth's mantle along a 30-mile stretch of the Newport-Inglewood Fault Zone in the Los Angeles Basin.