The researchers used ground-penetrating radar to explore beneath the playwright's tomb in Stratford-upon-Avon's Holy Trinity Church. Kevin Colls, who led the study, said the team found "an odd disturbance at the head end."
He said today the finding lends support to a claim that the Bard's skull was stolen by grave-robbers in the 18th century.
Colls said "it's very, very convincing to me that his skull isn't at Holy Trinity at all."
But Patrick Taylor, vicar of the church, said he was not convinced there is "sufficient evidence to conclude that his skull has been taken." He said there are no plans to disturb the grave to find out.