The Porter County sheriff’s office is warning northwest Indiana residents about a phone scam in which the caller claims to be a police officer with an arrest warrant.

A Chesterton, Indiana resident recently received a call on their cellphone from an “Officer John Pepe” from the “sheriff’s office,” purporting to have a “failure to appear” warrant for jury duty that was issued in the caller’s name, according to a statement from the Porter County sheriff’s office. The caller stayed on the phone with the victim as they drove to a gas station to purchase MoneyPak.com cards in various amounts to pay for the alleged offense, or else be arrested.

The call came from a Valparaiso listed cellphone, police said. If you call the number back, an automated recording states you have reached “the sheriff’s office civil processing division” and provides prompt numbers for alleged officers to be reached.

“These calls are NOT real calls,” the statement said.

Police warn the caller can be “very convincing and very threatening” and urge anyone who receives a call like this to hang up.

“The Porter County Sheriff’s Office, or any government agency for that matter, will NOT call you on the phone, instruct you to purchase gift cards for bond amounts and provide ‘us’ with the serial numbers or threaten to arrest you if you don’t follow through,” the statement said.