I got a letter from an investigation company asking me to get in contact. I know nothing about it. Why me?

The only thing the letter said was:
We act on behalf of a client and would be obliged if yu could telephone us on FREEPHONE **** **** ***
Yours sincerely *signiture*

I have been to their website and it hasn't told me anything about it just about what they investigate.
What does this mean?
Could it be me being investigated?
I'm really confused as to what this is about.
Please answer as soon as possible.

I know this is not a hoax because if it was then there wouldn't be all of mine and their details on such as a valid company name and website.

Hi I read that you have been on the company website, if this is a true investigation company you can check it out first before contacting, look for a data protection licence number, you can check with the information commissioner if it is a registered organisation, also to bear in mind Investigation companies are used by companies and general public to carry out debt collection. For peace of mind contact them before you give any personal details ask them who they are, who is the client, it may be something simple.

Personally, I would ignore it and assume it was a hoax of some kind.

scam or new way of advertisement

I!! chloi, Be very careful of these they can be dodgy, they may say" we have found in an old will money you are entitled to because you are a sole relative, a person who died X? years ago. Or some other such scheme; if you persue it, it could
cost a lot more than the worth, if anyting at all.
Also it could be if you open it and pursue the enquiery, then you have automaticly consented to pay for a contract you know nothing about.
Ignore such calls or, e-mails.