Simon Cowell says he feared his young son Eric had been kidnapped after he discovered his London home had been targeted by thieves.
The music mogul and his girlfriend Lauren Silverman were asleep in the house, along with their young son, when it was burgled in the early hours of Friday morning.
Simon has now revealed he initially feared the break-in was a kidnap attempt.
"It was nerve-racking. Lauren was woken up with me and we checked on Eric," Cowell told British newspaper the Sun on Sunday.
"That was the first thing we did, to make sure he was OK.
"Apart from the fact someone broke into my house and stole my stuff, which is scary, it could have been worse. Thankfully no one was hurt. But we have the worst guard dogs in the world. It's not what they stole, it's the fact they got into the house. That was the frightening thing, the idea someone was in my house."
Cowell was woken by a bodyguard at 2am and told that a thief had ransacked his safe, which contained jewellery and cash.
A local security guard, who patrols the exclusive London neighbourhood where Cowell lives, spotted the burglar drop a passport after he fled the scene.
"He saw the burglar leave and drop my passport," Cowell added. "He got out of his car, picked up the passport and realised it was mine.
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He approached the guy but the guy ran off. The guard then told us somebody had burgled the house. We didn't even know. He's got a big Christmas present coming."
Cowell said he will now increase security at his home, where he was previously targeted by a female intruder in 2012, who broke into the property and hid in a wardrobe.
"What's more concerning is how we stop people getting into this house. Wherever you live someone can get in. Maybe I have to get bigger guard dogs," he explains.
"This is the second time. A girl before, now a guy. That's what's scary. If a nutcase got in, that's what I'm worried about."
-AAP