Thousands of children across the country dressed up as Harry Potter characters for World Book Day but this school went one better with a visit from one of the stars of the blockbuster films.

Michael Gambon, who plays Professor Albus Dumbledore in some of the films based on JK Rowling's popular books, spent the morning with pupils and staff at Shears Green Junior School in Northfleet.

Sir Michael answered questions in assembly, signed autographs, posed for photos and even allowed the youngsters to interview him for their podcast.

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Staff knew the star was coming and all dressed as Harry Potter characters in his honour, but they kept it a secret from the pupils.

Deputy head Matt Paterson, who was as excited as the children, dressed as Dumbledore.

Mr Paterson said: "Everyone is still buzzing. He popped in yesterday morning and spoke to the adults first and we gave him a tour.

"Then he did an assembly with the whole school - 480 children - where they asked him questions.

"We showed some clips of him in Harry Potter and on Top Gear and then there was an open question and answer session.

"Some of the pupils interviewed him for their World Book Day podcast, it was an incredible interview.

"The children only knew him as Dumbledore but the staff knew him from all the films and television shows he's done over the years.

"He was such a nice guy, nothing was too much for him. He was so down to earth and laughed and joked. He referred to himself as Dumble'bore' saying he wasn't very interesting.

"He was very generous with his time and the children were really inspired."

Some questions posed by the children were Harry Potter-themed while others were about acting in general and one child even asked him about his favourite food.

The visit came about because Sir Michael, who lives in the area, is friends with a pupil's dad and had been spotted by staff in the playground picking the youngster up.

Teachers approached the star through the parent to ask if he would like to visit on World Book Day and Mr Paterson said he jumped at the chance.

Sir Michael began playing Hogwarts's headmaster in the third Harry Potter film, Harry Potter and the Prisoner of Azkaban, in 2004 following the death of Richard Harris who originally played the character.

He became a household name starring in The Singing Detective in 1986 and has appeared in numerous television and stage shows since.

In 2002 he appeared on the BBC's Top Gear programme and famously almost rolled a Suzuki Liana on a bend, which led to that part of the track being named Gambon in his honour.

He was knighted in 1998.