One of the UK's largest and most endangered spiders has been spotted for the first time in more than 25 years – just in time for Halloween.

The great fox-spider is listed as "critically endangered" and was feared to be extinct in the UK before it was rediscovered at a Ministry of Defence (MoD) training area in Surrey.

Previously it had not been seen since the early 1990s and had only ever been found at three sites in Dorset and Surrey.

Mike Waite, from the Surrey Wildlife Trust, said he was "over the moon" with the discovery.

He said: "This formidable-looking creature is an impressive beast, perfectly camouflaged and also largely nocturnal, and for all its size it has been remarkably elusive."

The arachnid-enthusiast spent two years searching late at night for the creature.

Finally, he discovered some unidentifiable immature spiderlings on MoD land managed by the Amphibian and Reptile Conservation Trust.

He then found several mature males and one female great fox-spider, which was 55mm, or just over two inches, in diameter including its hairy, spiny legs.

The great fox-spider - Alopecosa fabrilis - is one of the largest of the wolf-spider Lycosidae family of spiders. It is an opportunistic predator which hunts at night and is named for its wolf-like habit of chasing down its prey, across sandy terrain, over gravel and rocks before pouncing and capturing insects on the run.

The spider has eight black eyes and will immobilise its prey, including beetles, ants and smaller spiders, by injecting them with venom which liquifies the internal organs of the insect.

They shelter in silk-lined burrows or holes under rocks and Mr Waite now plans to continue his study to gauge the size of the population.

Naturalist and president of the British Arachnological Society Nick Baker said: "The prefix 'great' doesn't seem to do it justice, maybe it should be the fabulous, or fantastic fox-spider.

"Even if the back story of its rarity and its rediscovery wasn't taken into count, this spider is mega. It's about as handsome as a spider gets, it's big and now it's officially a member of the British fauna again.

"The rediscovery of the great fox-spider is indeed the most exciting thing to happen in wildlife circles for quite some time. Glad it's in safe hands."