A collection of Harry Potter books signed by JK Rowling has raised almost £20,000 for charity after an internet auction.

Considered one of just a few complete signed sets in the world, the seven books were kept under lock and key in an Aberdeenshire police station before they were sold on eBay for £18,200.

The money raised will go to Books Abroad, a charity which supplies books to children around the world.

JK Rowling’s mother in law, Barbara Murray, works for Books Abroad and the auction marks the charity’s 25th anniversary celebrations.

In that time, the Rhynie-based organisation has sent around two million free books around the world.