The quest to find the most mysterious particles in the Universe is entering a critical phase, scientists say.

An experiment located in the bottom of a gold mine in South Dakota, US, could offer the best chance yet of detecting dark matter.

Scientists believe this substance makes up more than a quarter of the cosmos, yet no-one has ever seen it directly.

Early results from this detector, called LUX, confirmed it was the most powerful experiment of its kind.

Rebecca Morelle reports for Newsnight.