JK Rowling has apologised to fans for killing off teacher Remus Lupin, as she marked the 18th anniversary of the Battle of Hogwarts.

The Harry Potter author tweets an apology every year on May 2, and told fans that she "didn't enjoy" and didn't originally intend to kill him off.

She has previously confessed to fans that she planned for Arthur Weasley - Ron's father - to die in the last battle, but then changed her mind when writing the fifth book.

Lupin, played by David Thewlis, was murdered by a Death Eater in the final battle, while his wife was killed by Bellatrix Lestrange, leaving their son Teddy an orphan.