Prof Maguire says that a majority of plays written in this era had more than one writer - but the iconic status of Shakespeare has meant a reluctance to consider his work in this way.
She says she is "very confident" that there is "a second hand" in the authorship of the play.
The research by Prof Maguire and Dr Emma Smith, from Oxford University's English faculty, suggests that the playwright Thomas Middleton, a contemporary of Shakespeare's, appears to be the likely candidate.
Of course there have always been people who thought that Shakespeare didn't write his own works (and they have been attributed to many of his contemporaries, though the best take on it by far is in the Thursday Next series (beginning with The Eyre Affair: A Thursday Next Novel).
The question of the authorship of Shakespeare's plays has been a continued source of speculation and conspiracy.
Prof Maguire says that there is no serious scholarship which challenges the idea that Shakespeare wrote the plays attributed to him.
At the same time there are those who thought that Shakespeare wrote the (King James) Bible.
There is not much records of Shakespeare´s personal life. Rumors arise from time to time that he did not write his plays, but the real author was Christopher Marlowe, or Queen Elizabeth or Edward De Vere (1550-1604), whom T.J. Looney identified in 1920 as the author of Shakespeare's plays. A large body of 'Oxfordians' have since built on this claim and the reluctance to believe that a man of humble origins could could create such magnificent works. According to some numerologists, Shakespeare wrote The King James Version of the Bible at the age of 46. Their "evidence": Shake is the 46th word of the 46th Psalm, Spear is the 46th word from the end in the 46th Psalm.
Well now it is all about multiple authors. Instead of E,J,P and D there are S (Shakespeare) and M (for Thomas Middleton).
Well, I suppose unless we borrow the Doctor's Tardis we will never know for sure. And at least it keeps some academics in business to come up with these theories. It in not way diminishes the brilliance of the plays themselves. And just like the Torah itself, logic and scientific study are not the important thing, but belief in the beauty and meaning of the words, and how they have changed the world.