The 5,000-year-old human bone found in the River Thames

On a fine September day last year, Simon Hunt took his boat down to the River Thames at Brentford, west London - just as he does most days.

But on that particular day, he spotted something lurking in the shallows.

Lying on the pebbles and rocks of the riverbed at low tide was a human femur, or upper leg bone.

Carbon dating has since indicated it to be more than 5,000 years old, meaning it had come from someone who lived in the late British Neolithic period - the end of the Stone Age.

Experts say it is dated between 3516 and 3365 BC and belonged to a person who was about 5ft 7in (170cm) tall, but it's not been possible to tell if they were male or female.

Video by Sarah Lee and David Perella