Queen Elizabeth II is descended from the Prophet Muhammed

This is not "news" (the original source dates from 1986), and to my knowledge it's not disputed, since the source is the inestimable Burke's Peerage:

Mixed in with Queen Elizabeth’s blue blood is the blood of the Moslem prophet Mohammed, according to Burke’s Peerage, the geneological guide to royalty. The relation came out when Harold B. Brooks-Baker, publishing director of Burke’s, wrote Prime Minister Margaret Thatcher to ask for better security for the royal family. ”The royal family’s direct descent from the prophet Mohammed cannot be relied upon to protect the royal family forever from Moslem terrorists,” he said. Probably realizing 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.”

Brooks-Baker said the British royal family is descended from Mohammed through the Arab kings of Seville, who once ruled Spain. By marriage, their blood passed to the European kings of Portugal and Castille, and through them to England’s 15th century King Edward IV. ‘ 

Additional commentary from Informed Comment's Juan Cole:

The Greater Mediterranean got all mixed up over millennia. Most Sicilians (i.e. most Italian-Americans) also have Arab Muslim ancestors. It works the other way around, too. It is obvious that a lot of Egyptians, Lebanese and Jordanians have descent from the Christian European Crusaders.

This is connected to just pointing out that having ancestors named Hussein is more common among Europeans and Americans than is usually realized. Elizabeth II can’t be descended from the Prophet Muhammad without also being descended from his grandson, the original Husayn / Hussein, since that is the line of descent of the Sayyids. 

All of which is just an illustration of the basic fact that all current humans are related to one another, and that race is a very artificial construct.