The operator of the damaged Fukushima Daiichi nuclear power plant has released a video taken by a drone showing an area beneath a reactor, which suffered a meltdown in the 2011 earthquake and tsunami.

Tokyo Electric Power Company sent a drone into the area beneath the No. 1 reactor on March 14 for the first time, and released the footage on Thursday.

It shows some components that move control rods fell from the bottom of the reactor where they normally sit. Agglomerated or icicle-shaped objects are seen attached to the tips of the components.

The company says the objects could include nuclear fuel debris which is a mixture of molten nuclear fuel and surrounding devices.

TEPCO officials say objects which had existed near the bottom of the reactor appear to have slipped from there due to the accident. They say the reactor may have suffered extensive damage.

Last year, TEPCO sent a robot probe into water accumulated inside the containment vessel of the No.1 reactor and confirmed there was accumulated material, which appeared to be fuel debris, at the bottom.

This time, the company surveyed the area above the water and closer to the reactor.

Experts estimate there is a total of 880 tons of fuel debris inside No. 1, 2 and 3 reactors. The No. 1 reactor is believed to have the largest amount of molten debris at the bottom of the containment vessel.

TEPCO plans to analyze data obtained from the survey in order to study ways to collect and remove the debris.