RESEARCHERS from the Bodleian Library have managed to reveal stunning images of a Mexican manuscript which were hidden for almost 500 years.

The Codex Selden, housed at the Oxford institution, had previously been obscured by a layer of plaster and chalk.

But using new high-tech imaging, the mysteries of the five-metre long strip of deer hide have been unearthed, and offer a tantalising look at early Mexican culture.

"After four or five years of trying different techniques, we’ve been able to reveal an abundance of images without damaging this extremely vulnerable item," said Ludo Snijders from Leiden University, who conducted the research with David Howell from the Bodleian Libraries and Tim Zaman from the University of Delft.

The item is extremely rare – fewer than 20 are known to have survived pre-colonial and early colonial Mexico – and dates to about 1560.

It is one of only five surviving manuscripts from the 'Mixtec' area, now the Oaxaca region.

The codex uses a complex system of pictures, symbols and bright colours to narrate centuries of conquering dynasties as well as wars and the history of ancient cities – providing the best insight into the history and culture of early Mexico.

Mr Snijders said: "What’s interesting is that the text we’ve found doesn’t match that of other early Mixtec manuscripts. The genealogy we see appears to be unique, which means it may prove invaluable for the interpretation of archaeological remains from southern Mexico."

Some pages feature more than 20 characters sitting or standing in the same direction. Similar scenes have been found on other Mixtec manuscripts, representing a King and his council.

The researchers analysed seven pages of the codex for this study and revealed other images including people walking with sticks and spears, women with red hair or headdresses and place signs containing the glyphs for rivers.

The paints used to crate the vibrant images are organic and do not absorb X-rays, meaning traditional methods could not be used in trying to get a glimpse of the codex's fascinating stories.

Working with the humanities division in the University of Oxford, the Bodleian acquired a hyperspectral scanner in 2014 with the support of the university’s Fell Fund – and the equipment was able to unmask the past.

David Howell, head of heritage science at the Bodleian Libraries, said: "This is very much a new technique, and we’ve learned valuable lessons about how to use hyperspectral imaging in the future both for this very fragile manuscript and for countless others like it."

Researchers are continuing to analyse the remainder of the document with the aim of reconstructing the entire hidden imagery, allowing the text to be interpreted more fully.