Hollywood's habit of playing with historical facts is leading schoolchildren to get it wrong too – even if they read the true story in classrooms, a new academic study shows.

Researchers have found that film is an incredibly powerful tool for teaching children about the past which can greatly increase historical knowledge.

However, it is so powerful that if the facts are wrong, pupils are more likely to believe them even if they are told otherwise by text books or teachers, they say.

Mr Butler, who published in the journal Psychological Science, recommends that teachers carry on showing films in classrooms but before it starts make a point of telling the children to look out for particular mistakes.