An 8th-century manuscript showing a page from the Quran, Islam's holy text, has been found to show Coptic Christian writing that had been erased and over-written.
The finding was described as 'very important... for the history of the Quran and early Islam', by French scholar Dr Eléonore Cellard, who researched the text, according to the Daily Express.
She added: 'We have here a witness of cultural interactions between different religious communities.'
The Quran manuscript shows faint markings of Christian text – from the Old Testament book of Deuteronomy – erased and replaced by the Islamic inscription. Such a text, showing traces of its earlier content, known as a palimpsest, and was not uncommon in antiquity.
The manuscript is believed to have been produced in Egypt, where the Coptic Christian community originated and still represents about 10 per cent of the majority-Muslim population. The dating of the original Christian writing is now almost impossible to ascertain without risking damage to the artefact.
The palimpsest is now up for auction at Christie's auction house, with a guide price of £80,000-120,000.
Christie's specialist Romain Pingannaud said of the ancient find: 'It's quite extraordinary. Once you know it's there, you can only see it, it becomes so obvious. We missed it at the beginning.
'It's fascinating, particularly because it's the only example where you have an Arabic text on top of a non-Arabic text.
'And what's even more fascinating is it is on top of passages from the Old Testament...It shows the contact between communities in the first centuries of Islam; it's very relevant.'