Delete a key from keyring, using gpgme

Vit Sykacek Vit Sykacek" <
Thu Oct 10 08:54:36 2002

I'm using gpgme to use some functions of gpg in my code. 
All other functions are working good, but deleting of key  
doesn't work. It returns gpgme_no_error, but key stays in  
keyring. Here's line of my code: 
err = gpgme_op_delete(ctx, key, 1); 
Context and key are not null. Does anyone know, where  
is the prob ?