It can be any body that lends out money and charges interest.
In Denmark the government only lends you money in a very limited set of cases, usually related to you getting a place to live, and they don't charge interest. Though investor are technically lending you money, they do not set the interest rate. So it can't be any of those.
The bank sets the interest rate on the loans the provide, so they are an option. But it could also be a quick loan service, or maybe even a mafia.
It can't be a single person, since "de" implies more than one person.