A literary group's claim that William Shakespeare was not the author of his plays has been described as "nonsense" by the Shakespeare Birthplace Trust.
William Shakespeare was not the real author, the De Vere Society says
The De Vere Society is marking the 400th anniversary of the death of Elizabethan nobleman Edward de Vere, who it says is the "real Shakespeare".
"To put it politely, they're barking up the wrong tree," the Birthplace Trust's chairman Professor Stanley Wells said.
He described it as the latest in a line of Shakespeare "conspiracy theories".
The De Vere Society says de Vere, Earl of Oxford, who lived from 1550 to 1604, used "William Shakespeare" as a pen name.
De Vere was much better educated, had travelled widely and was a member of Elizabeth I's court, it says, and the "historical" Shakespeare we know of came from a more modest upbringing.
"It is time to accept that the name Shakespeare was almost certainly a pseudonym for the real writer of genius," a spokesman for the group said.
"We now need to look for the author elsewhere in the Elizabethan world."
But Prof Wells said the society's views were "nonsensical".
"Edward de Vere did not write the works of Shakespeare, Shakespeare wrote the works of Shakespeare," he told BBC News Online.
He said there was a long history of groups trying to prove Shakespeare had not written the plays.
"They have quite a large following. Like every organisation of this kind, they ignore the basic evidence and construct conspiracy theories."
Prof Wells said de Vere had led a "busy life" and he found it hard to believe the earl had managed to write so many "masterpieces" at the same time.
Thursday is the anniversary of de Vere's death and The De Vere Society is planning more celebrations in London on Saturday.
Over the years, other theories about who wrote Shakespeare's plays have included claims they were written by playwright Francis Bacon and poet Christopher Marlowe.