Researchers said Thursday they have identified the remains of Nicolaus Copernicus by comparing DNA from a skeleton and hair retrieved from one of the 16th-century astronomer's books.

The findings could put an end to centuries of speculation about the exact resting spot of Copernicus, a priest and astronomer whose theories placed the sun, not the Earth, at the centre of the universe.

It wasn't until centuries later that astronomers found evidence the sun was not the centre of the universe, but rather one of billions of billions of stars, but at the time, it was a radical departure from the belief that the Earth was at the centre of the universe.

Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull that his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.

The reconstruction shows a broken nose and other features that resemble a self-portrait of Copernicus, and the skull bears a cut mark above the left eye that corresponds with a scar shown in the painting.

Moreover, the skull belonged to a man aged around 70 — Copernicus's age when he died in 1543.

In addition, Swedish genetics expert Marie Allen found that DNA from a tooth and femur bone matched that taken from two hairs retrieved from a book that the 16th-century Polish astronomer owned, which is kept at a library of Sweden's Uppsala University where Allen works.

Gassowski is head of the Archaeology and Anthropology Institute in Pultusk, in central Poland, and Allen works at the Rudbeck Laboratory of the Genetics and Pathology Department of Uppsala University.

Copernicus was known to have been buried in the 14th-century Frombork Cathedral where he served as a canon, but his grave was not marked. The bones found by Gassowski were located under floor tiles near one of the altars.

Gassowski's team started his search in 2004, on request from regional Catholic bishop, Jacek Jezierski.

Copernicus is believed to have come up with his main idea of the sun at the centre of the universe between 1508 and 1514, and during those years wrote a manuscript commonly known as Commentariolus (Little Commentary).

His final thesis was only published, however, in the year of his death. His ideas challenged the Bible, the Roman Catholic church and past theories, and they had important consequences for future thinkers, including Galileo, Descartes and Newton.