The term "person of interest" is normally used in criminal cases. Being in ordinary civil debt is not a crime and you cannot be subject to arrest for it. They are just trying to scare some money out of you. Don't fall for it. Ignore and block these calls.
Do you have anything on Kaplan & Associates? If so, this woman could use the information over here: http://800notes.com/Phone.aspx/1-888-684-2268#p1018359892498205586
Michelle Williams calls and tells me I am a person of interest in an ongoing investigation - yeah, whatever, then another call from Michelle Williams, except this one has a different voice than the first one...so come on if you going to scam folks, at least use the same female voice! States she is fro ESA and push number 1 to speak to an arbitrator. Whole conversation is such a joke!