Have you booked the villa through this site? If not I would give this site a try.

All villas on this site have to be verified every 6 months. This means the owners have to prove to th epeople running the site that they do infact own the villa.

You could always ask the owner for the phone number of their Management Company to check them out as well. Most owners would also be happy to provide you with referrances if you were unsure.

Most owners will ask for full payment between 8 - 10 weeks before your holiday so this is not unusual. You will also have an address for the owner and they should also give you a telephone contact as well as email.

I would comment however that £400 per week at peak time is a bit on the cheap side, so do find out all you can about the villa before commiting. As mentioned earlier if you are unsure take a look at the 3 links on this site.