They have already received 300 signatures for their "declaration of reasonable doubt," which was made in hopes of prompting further research into the issue, said the BBC Sunday.
"I subscribe to the group theory. I don't think anybody could do it on their own," said Jacobi.
The 287-member Shakespeare Authorship Coalition said it does not believe Shakespeare, a commoner born into an illiterate household, could have written plays about law.
Conspiracy theories have circulated that a number of writers could have used Shakespeare as a pen name, including playwright Christopher Marlowe, nobleman Edward de Vere and Francis Bacon.
"I think the leading light was probably de Vere as I agree that an author writes about his own experience, his own life and personalities," said Jacobi.
2014: The Year in Fashion [PHOTOS]
Polly Bergen, Emmy Award-winning actress, dies