Historians believe the Queen is a descendant to the founder of Islam - after tracing her family tree back 43 generations.
The claim would make the British monarch a distant ancestor of the Prophet Muhammad.
The findings were first published in 1986 by Burke's Peerage, a British authority on royal pedigrees, the Daily Mail reported.
But the claim has recently resurfaced after a Moroccan newspaper said it had traced the queen's lineage back to the Prophet.
According to their findings, Elizabeth II's bloodline runs through the Earl of Cambridge in the 14th century, across medieval Muslim Spain, to Fatima, the Prophet's daughter.
Although disputed by some historians, genealogical records of early-medieval Spain also support the claim and it has also been verified by Ali Gomaa, the former grand mufti of Egypt.
Burke's publishing director wrote to the-then Prime Minster Margaret Thatcher in 1986 calling for increased security for the royal family.
The claim has been verified by Ali Gomaa, the former grand mufti of Egypt. Photo / Getty Images
"The royal family's direct descent from the prophet Mohammed cannot be relied upon to protect the royal family forever from Moslem terrorists," he wrote to Thatcher.
Recognising the connection would be a surprise to many, he added, "It is little known by the British people that the blood of Mohammed flows in the veins of the queen. However, all Moslem religious leaders are proud of this fact."
A study came out in 2008 from Burke's Peerage suggesting the Queen's connection to the Prophet Muhammad.
It claimed the Queen descends from a Muslim princess called Zaida, who fled her home town of Seville in the 11th century before converting to Christianity.
Zaida was the fourth wife of King Al-Mu'tamid ibn Abbad of Seville. She bore him a son Sancho, whose descendant later married the Earl of Cambridge in the 11th century.
But British magazine the Spectator points out Zaida's origins are 'debatable'. Some historians believe she was the daughter of a wine-drinking caliph descended from the Prophet. Others say she married into his family.
The reaction to the Queen's reported links to the Prophet have been mixed.
Abdelhamid Al-Auouni welcomed the news in his piece in Moroccan newspaper Al-Ousboue, writing: "It builds a bridge between our two religions and kingdoms."
Meanwhile a tongue-in-cheek headline on the Arab Atheist Network's web forum read: "Queen Elizabeth must claim her right to rule Muslims."
One person on internet forum Reddit rubbished the claims however, writing: "This is just propaganda used by the British monarchy to appease the growing number of Muslim subjects."
