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A set of stone flakes shaped more than 3.3 million years ago could be the world's oldest tools created by early human ancestors, according to researchers.

Archaeologists have revealed that they have discovered 20 stone flakes and anvils - used to help shape the tools - just west of Lake Turkana in Kenya.

The discovery could fundamentally change the current view of human evolution as - if correct - the date of the stone tools is 700,000 years older than any others found previously.

The stone tools were discovered buried in sediment along the west coast of Lake Turkana (above) in Kenya

It means that ancient human ancestors were creating tools hundreds of thousands of years before the appearance of the first 'man' - the start of our branch of the evolutionary tree known as Homo.

Many experts have long believed that it was the use of stone tools by early species of Homo like Homo habilis and Homo erectus that helped set them apart from other human-like species.

Scientists behind the discovery now believe ancient species known as Australopithecines - typified by the fossilised skeleton called Lucy - or Kenyanthropus made the tools.

Professor Sonia Harmand, a palaeolithic archaeologist at Stony Brook University in New York who led the team that discovered the tools, said they stumbled across them by accident.

The team had been searching for the site where a controversial human relative called Kenyanthropus platyops had been discovered in 1998.

But after taking a wrong turn they came across another area and spotted what looked like stone tools on the sandy surface.

Professor Harmand, who was presenting her findings at the annual meeting of the Paleoanthropology Society, said: 'The artifacts were clearly knapped [created by intentional flaking] and not the result of accidental fracture of rocks.'

The tools were found at a site known as Lomekwi 3, just west of Lake Turkana in Kenya.

By excavating down into the sandy soil, the team discovered a series of sharp stone flakes and cores - the rocks the stones are knocked off.

They also found anvils that were apparently used to hold the cores as the flakes were struck off. In one case the team were able to fit a flake back to its original core.

A further 130 stone tools were discovered on the surface. 

Each of the stones showed distinctive patterns that suggest they had been struck and shaped by human ancestors.

As some tools were locked inside sediment left behind by the receding desert lake, the researchers were able to accurately estimate the time when they were dropped there.

By tracking changes in the Earth's magnetic field recorded in the sediment, the researchers were able to pinpoint the date to 3.3 million years ago.

This skull of Kenyanthropus platyops was found close to the site of the stone tools in 1999 close to Lake Turkana in Kenya and may be the species responsible for creating the stone flakes that have been discovered

This stone tool - known as an Olduvai chopper - on display at the British Museum is around 1.8 million years old was thought to be one of the earliest examples of stone that had been used by ancient human ancestors

These early stone tools found in Ethiopia are thought to be around 1.7 million years and were used as choppers

This is close to the date of another piece of controversial evidence found in 2010 that suggested stone tools were used long before the appearance of the Homo species on Earth.

Researchers working in Dikika in Ethiopia - where an Australopithecine child was discovered- reported they had found cut marks on animal bones dated to 3.4 million years ago.

Their claim that these had been made by human ancestors using tools were hugely controversial.

Now the latest discovery is the strongest evidence yet that these early humans did have ability to make and use tools rather than being primative creatures.

Until the recent discovery, the oldest stone tools to be discovered were in Gona, Ethiopia and were thought to have been made by early Homo species - possibly Homo habilis.

The stone tools may have been made by relatives of 'Lucy', a female Australopithecus afarensis that lived 3.2 million years ago who is shown above in a reconstruction at the Houston Museum of Natural Science in Texas

Recent discoveries have suggested that the Homo genus first began around 2.8 million years ago, but the tools discovered at Lake Turkana are 500,000 years older than that.

As they were found close to the site where Kenyanthropus platyops was discovered - which some say was actually a species of Australopithecine - it suggests they made the tools.

Professor Harmand, whose team are preparing a paper on the discovery for publication in the journal Nature, told the Paleoanthropology Society that the Lomekwi 3 tools had been created by 'knappers with a developing understanding of the fracture properties of stone'.

She said they were made using simple hammer techniques and combined battering the stones to break of flakes and a technique called core reduction.

She said: 'The Lomekwi 3 tools mark a new beginning to the known archaeological record.'

According to Alison Brooks, an anthropologist at George Washington University in Washington DC, the finds are 'very exciting.

She told the journal Science: 'They could not have been created by natural forces.' that the She added that technology shown in the tools may have actually played a major role in the emergence of our genus - Homo.

This fossilised jawbone with teeth still in place is thought to belong to the earliest member of the Homo genus 2.8 million years ago but this is still 500,000 years short of the time when stone tools were being used