I purchased UK hosting for my site. I hired a Indian programmer to work on my site and by mistake due to wrong coding around 8000 emails were sent to his own id through the hosting server and the web host has stopped my site and he is not returning my site's database.

I dont have a backup :(

The hosting people are telling this it is a SPAM, but it is not. Due to coding error the emails were sent to the 2 programmer id's only and not to anybody else's email id.

Please reply, what I should do to get back my database of the site

Tell the hosting company that the emails were only sent to the programers themselves, if they say otherwise, ask for proof stating their claim.

It may be a possibility that the indian programmers you hired really were spammers and just used the hosting you provided to spam.

Thats what you get for out-sourcing something like that. My dumbass friend out-sourced to a programmer in India also and paid $10,000 and waited over 6 months and still didn't get what he wanted. I could have done it here for $5,000 in one month, but he never asked me.