The easy solution would be to say that you didn't have a previous character.
Technically, it's poor IC/OOC Separation to ask such a thing, but at the same time, given how poor players tend to separate on their own, I see the reasoning. Its the catch 22 of our game. We tell people that their past lives are the past, but more often than not, while the character may change, the person behind the character has the same persona. :/
They are permitted to ask. They are permitted to reject you for any reason they like, even if they just don't like you as an OOC entity. None of those things are or can be monitored. IC/OOC separation is typically only bannable when it involves the transfer of assets from your old to your new character, or such a behavior. Beyond that, it's poor RP but there is no rule against poor RP.
So as has been suggested, you are absolutely free to lie about your past characters. They can ask and you can lie; neither of those things violate any rules.
Regardless of what has been said, the same questionnaire is sent to all new recruits which includes precisely what I've already listed. I'm sure any member of the NR Recruitment Team would be more than willing to forward the questionnaire if it were ever necessary.