Researchers have discovered that the highest mountain in the world continues to grow by about two millimetres per year because it is being pushed upwards by a nearby river.

The river is cutting into a landscape around the mountain and has increased Everest's height by between 15 and 50 metres over the past 89,000 years.

Dr. Xu Han, lead author of the study at the China University of Geosciences, said: "The changing height of Mount Everest really highlights the dynamic nature of the Earth's service.

"The interaction between the erosion of the Arun river and the upward pressure of the Earth's mantle gives Mount Everest a boost, pushing it up higher than it would otherwise be."

Co-author Adam Smith, a PhD student at University College London (UCL) Earth Sciences, added: "Mount Everest is a remarkable mountain of myth and legend and it's still growing."