Professor Kathryn Sutherland of Oxford University reached her conclusion while studying 1,100 original handwritten pages of Austen’s unpublished writings.
The manuscripts, she states, feature blots, crossing outs and “a powerful counter-grammatical way of writing”.
She adds: “The polished punctuation and epigrammatic style we see in Emma and Persuasion is simply not there.”
Professor Sutherland of the Faculty of English Language and Literature claims her findings refute the notion of Austen as “a perfect stylist”.
It suggests, she continues, that someone else was “heavily involved” in the editing process.
She believes that person to be William Gifford, an editor who worked for Austen’s publisher John Murray II.