A puzzling cache of stone figures covered in mysterious symbols could be the first evidence of a "lost civilisation".

The mystery carvings could hold the key to a lost civilisation [Credit: University of Haifa]

The bizarre figurines were first discovered in the 19th century by a local monk who claimed he was led to the "secret stash" by a dying woman who lived in a hut in the Puerto Rican mountains.

It was previously believed the figurines may have been created as a hoax by the monk, however archaeologists at Israel’s University of Haifa have recently discredited this theory.

Using microscopic testing, they have been able to confirm the statuettes were carved in the later 14th or early 15th century.

“To date, we have not found any similar carved stone art objects from this region of America, and this is why many researchers assumed that they must be fake," researcher Dr Iris Groman-Yaroslavsky said.

Reniel Rodríguez Ramos examining some of the Puerto Rican figurines at Haifa University [Credit: University of Haifa]

 

"However, the microscopic tests we performed show beyond any doubt that the stones were carved around 600 years ago."

 

According to the research, the stones were "unequivocally carved in ancient times".

"Under the microscope, we can see the erosion of the stones and the brown-grey patina that is typically found when items have been buried or exposed to the ravages of nature for extensive periods," he explained.

"The items are made from a mineral that was originally a greenish black, but the erosion covers the engravings across the entire item, and there is no evidence of any modern manipulation that would have exposed the natural surface of the mineral.

El Yunque view from Yokahu Tower on a clear day, mountain forests of Puerto Rico [Credit: WikiCommons]

"The processing marks on the items show that special chiselling tools were used, and all the items appear to share a unique style."

Researchers also found the objects had previously been coated in red paint and gold - a fact supporting evidence the stones were produced locally, as gold and ochre mines can both be found in Puerto Rico.

While the discovery still puzzles researchers, they will continue to investigate "the existence of a previously unknown pre-Columbian civilisation waiting to be uncovered".