Temporary Live in Guest affecting my credit rating!?

[W4NTED]

My nephew from down under has moved in with me around a month ago and is planning on finding a job and settling down in the UK. I agreed to support him until he finds his feet. He went and opened a bank account with a high street bank using my address and his NI number is also being applied at my address. I am in the middle of a remortgage application and the bank have asked me who this chap is as he is financially linked to my address.

Would him being at my home affect my chances of getting this mortgage? Any help appreciated as I can't find anything online about this.

[W4NTED]

Thanks that is reassuring! Was going to kick his arse back to roo land LOL