04 1.4 C2 Beeping.

[Devilstreak]

Just had a phone call from a friend, her C2 is beeping without the key in the ignition. (a loud beep every second or so) It is still beeping to itself in the car park after she has locked it.

Has anyone seen this before? Or know what it is? I can't go and have a look till 5pm.

Thanks in advance.