If you just deleted them they are still there, only not immediately visible by the OS. The deletion of files is simply a removal from their entries in the file index. If you want to completely erase files beyond any recovery, you must use proper safety tools that will, for instance, fill that space with zeros.

Having said that, if you are not writing a lot of information on your server, chances are that those files haven't been overwritten yet thus they can be recovered with the appropriate recovery tools.

Use Google to search for "file recovery tools" and good luck!