Hijacking this for visibility.

If the recruiter asks repeatedly, a trick that I learned is to answer that it's in your employee confidentiality agreement not to discuss the terms of your employment. It's arguably a true statement as well (in case you were concerned about telling a white lie)--your employer could be considering your salary as confidential because they obviously haven't disclosed it publicly, so you are taking a very conservative approach on the confidentiality terms in most contracts.

edit: the statement doesn't need to be legally defensible, it gives you an opportunity to redirect and ask what they are willing to pay for the position or to learn about their benefits package.