Dear Alan,
Defamation is defined as being an action by a person (or many people) that has destroyed another person's reputation either by verbal or written information. In South Australia, the tort of defamation is governed by common law and the Defamation Act 2005 (SA).
The Plaintiff (the person bringing the case) has the burden of proof to prove that the information that was provided was false, the information must of been communicated either verbally or written to a third party and the information that was communicated to a third person must have reference to the particular person.
Looking at the particular aspects of your situation it seems unlikely that the action of the recruiter would be deemed defamatory as the information that was passed on to the third parties was your resume - which is a true document.