Mystery starting problem

[The Cupra Kid]

Help! Parents Micra wouldn't start. Taken to Nissan who cant find anything wrong. They can start the engine, and when started runs fine, but not using either the main key, or the backup. Any suggestions/ solutions

 

[Hooky]

Only the obvious.....ask nissan how they managed to start the car! if they have bypassed the key system then the key system must be the problem