Ben Affleck is so paranoid about intruders he built a panic room in his former house, according to the property’s new owner, director Kevin Smith.

The filmmaker bought the Good Will Hunting actor’s Hollywood home in 2003 and was surprised when he first discovered the secret chamber.

Affleck installed a panic room in the house hidden behind a bookcase – featuring a video monitor, phone and a safe.

But Smith was less than impressed with the feature’s dimensions.

He reveals, “He’s showing us around and says, ‘I can’t wait to show you this, when I was building this, I knew you’d love it… He brings me into this office off the master bedroom, which is now my master bedroom. And in this office is a beautiful bookcase and he says, ‘Watch this.’

“He reaches over and under the bookshelf there is a hidden button ‘click’ and the bookshelf pushes back, Batman style. At that point I fully expected Ben to say, ‘Let’s go fight crime in Los Angeles!’ But it wasn’t – he says, ‘Dude I built a panic room!’ I couldn’t wait to go into it, I was expecting The Bat Cave… It was tiny. It might have been a small bathroom back in the day.

“The panic room had a safe in it, a video monitor and a phone… in case someone came you could hide in there. From the outside, it was very Hollywood. It was astounding. The moment you got inside…it’s not what you’re hoping for from Ben Affleck’s secret room. There is not a staircase that leads you down to a ski boat that takes you onto the bay.

“We don’t even use it any more – it’s filled with our kids’ old Christmas gifts. Plus, no one’s panicked in this house. No one’s trying to come in here and steal me. I’m not Ben Affleck.”