Files can't be opened and look likes it is just a ´shell´.

I already posted a message yesterday on CR2 files that won´t open (nor in LR, nor in Finder).

I now found out that although in the top of the info-display it says that it is a 31,9MB file, but at the same time it says that the size is only 8KB on the disk. 

Anyone a suggestion where this could be caused by?

Thanks in advance,

Jacqueline