Amanda Seyfried accidentally boarded a plane with her pocketknife still in her possession because it was undetected by airport security.

Huffingtonpost.com reports that one she realised what happened, she took a photo of it and Tweeted to inform TSA (Transportation Security Administration) so that things like this hopefully don't happen again. It happened on Friday.

Seyfried wrote: 'Dear TSA: This Swiss Army knife wasn't detected through security and I unknowingly carried it on board. Scary!' 'Yes, scary indeed!'