Whereupon someone promptly began making fraudulent withdrawals from his account.
Clarkson, 47, writing in his column in the Sunday Times, decried the furore last year after CDs disappeared containing the banking details of 7 million families.
The loss led to fears of mass identity theft with people's bank accounts open to internet scams.
At the time he wrote: "I have never known such a palaver about nothing. The fact is we happily hand over cheques to all sorts of unsavoury people all day long without a moment's thought. We have nothing to fear."
However, yesterday he told readers he had opened his bank statement to find a direct debit had been set up in his name and £500 taken out of his account.
"The bank cannot find out who did this because of the Data Protection Act and they cannot stop it from happening again," he said. "I was wrong and I have been punished for my mistake."
(Image: crop from Books, a Creative Commons Attribution-ShareAlike photo from William Hook's Flickr stream)
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.