Con artists have now added a new twist to a popular telephone scam in Wyoming, according to Sweetwater County Sheriff Mike Lowell.

The sheriff says the IRS phone scam, in which phony IRS agents try to extort supposed back tax payments using the threat of an arrest or similar consequences, has been around for a long time.

But scammers are now using a ''new and improved" version of the classic scam.

The major change is that recorded phone messages are being used to target victims who screen their calls. The phony messages about bogus back taxes tell victims to call back immediately. If that happens the swindlers know they have a possible victim, because the person was worried enough to call back.

While some of the recorded messages sound very believable,  the fact is the IRS always makes contact with delinquent taxpayers using a letter, not a phone call.

There are some other red flags that the call is a scam:

· Knowledge of the intended victim's Social Security number or its last four digits.
· Recitation of the bogus IRS agent's badge number.
· During the call, the sound of other, similar conversations can be heard in the background.
· The caller becomes rude and hostile and hangs up.
· Follow-up calls from a different person claiming to be an IRS agent.

Taxpayers can always find out if they actually owe back taxes by calling the IRS at 1-800-829-1040.