A new species of spider discovered in western Queensland has a venom that could potentially be useful in the production of pharmaceuticals, a scientist studying the animal has said.

The tarantula, which is yet to have been given a scientific name, was discovered in a garden on a property near Longreach.

Queensland Museum's Dr Robert Raven said the Longreach species was one of 20 from across Australia that he was currently studying.

Dr Raven said it was important to know more about the Longreach species because its venom may be useful for medicinal purposes.

"These things have killed dogs and cats quite easily, and anything that affects a dog or a cat is particularly very exciting from the point of view of looking at pharmaceutical applications for the venom," he said.

Dr Raven says tarantulas have been found in the Longreach area for decades.

But he said identifying them as a different, undescribed species is a new conclusion.

"There have been collections that have made from the Longreach area dating back into the 1930s, but we have only recently come to the conclusion that it is a different species to the other ones," he said.

"Longreach is about the point where everything starts - and the exciting thing about Longreach is that it has some amazing cultural things, and natural history is no different.

"It is an interesting changeover point for natural history just around there."

Dr Raven has been studying spiders for almost 40 years, and said more research was needed to find out more about the new species.

"They are tarantulas, and they are on a protected list with Parks in Australia," Dr Raven said.

"The thing is that people like these things because they are so big, they get them into the markets and they sell them for about $250 each for a medium-sized specimen.

"So as these things are being taken out of the wild, we are actually heavily depleting what's a fairly limited local population."

Dr Raven said he hoped to have a scientific paper on the new spider species completed next month, but it may be some time before it is published.

'Not everyone's idea of a pet'

The spider was found earlier this year by friends of Longreach grazier and Queensland Museum honorary fellow Angus Emmott.

Angus Emmott is feeding one of the newly discovered spiders. ( ABC News: Chrissy Arthur )

Mr Emmott said the spider came from the Mitchell grass downs on the eastern side of the Thomson River.

"Friends of mine found it in their garden and they were concerned about it because it is a very large spider," he said.

"If you were to sit on your hand with their legs out, they sort of take up the whole of your hand.

"They are fair lumps of spiders, similar to a golf ball, and they have these burrows that go straight down."

Mr Emmott said he had a live one that he was feeding.

"He is quite a cute little fellow, well big fellow, but it is probably not everyone's idea of a pet," he said.