Concerned is how anyone might feel after listening to the voicemail Beaumont resident Don Colwell received.

"Hi, this is the Internal Revenue Service calling you to call back immediately regarding a lawsuit and legal charges, which have been filed against you by the headquarters," said a very official-sounding voice, eventually listing a number for Colwell to call to settle the case.

Colwell dialed it right away, but said he started having some doubts once he heard the voice on the other end of the line.

"He went through the spiel: 'They filed charges and there's a lawsuit against you. We're trying to prevent you from getting arrested,'" said Colwell.

That's when he realized someone was trying to scam him and he's afraid others will fall for it.

"If they were to have heard this, they very well may have taken it seriously. They may very well have thought, 'Oh, my God. I'm in trouble. I need to take care of this right now.' That's what I'm concerned about," Colwell said.

In fact, that's exactly what happened to many Southeast Texans, according to the Better Business Bureau's Jay Sheppard.

"At least a couple of times a week, we hear from somebody who has sent money to a scammer because of the IRS call," she said. "I talked to someone who sent $5,000. That is money they will never get back."

In Texas alone, the scam has claimed 742 victims and $3.5 million in less than four years, according to the IRS. But Sheppard worries those numbers don't tell the whole story.

"I truly believe that is the tip of the iceberg. The reason I believe that is because there's really no statistic that can accurately gauge that. Because so many people who send that money off are embarrassed and they don't report it," she said.

Clay Sanford with IRS Media Relations said the scam has been on the increase for the past two or three years. He said the scammers usually call in from a fake U.S. phone number, demand immediate payment and sometimes threaten arrest or deportation.

If you receive that call, Sanford said there's really only one thing for you to do: "Hang up before you give up any personal information."

Sanford pointed out it's also important to report the calls, whether or not you fall for it. If you have received an IRS scam call, click here to let investigators know.