There is a particularly disgusting spam email going around, purporting to come from either "Kevin" or "Searle". It invites you to send a text to a UK based number or send an email to a yahoo account that will gain you access to child porn. In the last 24 hours I have received 10 of them.
Suggestions made on a google newsgroup imply that the phone number involved could be that of a UK based anti-spam organisation but I haven't got the bollocks to find out. If it is, it's a sick joke.
Report anything like this in the UK to the Internet Watch Foundation. There are instructions on how to copy the email source code on the site. You can also report to your ISP, they should be able to point you at the correct agency.
It probably is a hoax but don't even bother trying to find out.