So the debt is most likely credit card, although they are just referring to another debt collector in a Scandinavian country they are collecting on behalf of. (Intrum Capital). I moved nearly 10 years ago , and have  not paid anything or dealt with any of then in that time. I know the creditors can "renew" the statue barred status in the country every 10 years , but I'm not sure they have done so. I believe (even though I'm not sure what debt they would be referring to) would be that old.