Updated

The operator of Japan's crippled Fukushima nuclear plant says a long telescopic probe has successfully captured images of some melted fuel inside one of its three damaged reactors, providing crucial information for its cleanup.

Tokyo Electric Power Co. said Friday the fishing rod-like device carrying a camera went deep into the plant's Unit 2 primary containment vessel. The images showed that at least part of the fuel breached the core, falling to the vessel's floor.

Melted fuel has previously only been documented inside Unit 3.

A massive earthquake and tsunami in 2011 caused three reactors at the Fukushima plant to melt.

Determining the location of the melted fuel is crucial in planning for its removal, the hardest process in the plant's decades-long decommissioning.