A Hertfordshire Fire and Rescue Service spokesman confirmed 15 crews were sent to the scene when the fire broke out. Studios in Leavesden in Hertfordshire at 11.29pm on Wednesday 10 July.
The set was not being used at the time and there were no injuries, it added.
Fire and rescue crews were called to the film studios in Hertfordshire, just outside London, late last night United Kingdom time.
"The set was not getting used on the time of the hearth".
Firefighters have put out a blaze at the Warner Bros. studio near London, where all eight Harry Potter movies were filmed, after tackling the fire for over twelve hours.
"It was still going strong at about 1 a.m".
It was converted for film use in 1994 for Pierce Brosnan's first Bond film GoldenEye and has been a popular site for producers ever since.
The studio, which is the place the Harry Potter motion pictures had been made, can also be the house of the Harry Potter studio tour.
The Leavesden-based studios have also been involved in the production of The Dark Kight, Inception, Star Wars Episode I: The Phantom Menace and Jason Bourne.
A fire has broken out at Warner Bros studios in Watford - the famous filming location in which Harry Potter was filmed.
A spokesman for Warner Bros would not comment on the fire other than to confirm it was ongoing.
"Eighteen fireplace engines and help automobiles, are at present on the scene as crews proceed to sort out the hearth".
Locals allegedly began smelling smoke late last night and have since watched it swirl up over the studios.