The caller posing as a Hawaiian Electric Co. employee delivered a spiel with convincing detail, right down to his correct pronunciation of Hawaiian place names and an in-depth knowledge of how the utility’s billing system worked.

The voice informed Young Laundry & Dry Cleaning General Manager Mike Drace that the laundry company failed to pay a monthly electric bill for one of its Hono­lulu stores and had ignored several warnings to clear up the arrears. Unless Drace paid the bill within the hour using a money transfer service, the power to the store would be cut off.

The standard bill payment method used by Young Laundry would not be sufficient, the caller said, because the amount wouldn’t be credited to HECO until after midnight, and that would be too late to prevent the electricity from being disconnected.

The caller even knew the approximate amount of the store’s usual monthly payment to HECO. The final touch was that the call came late on a Friday, when Drace could not reach anyone in the company’s accounting office in Arizona to verify whether the electric bill indeed had not been paid.

"We’ve gotten similar calls before and I’ve never fallen for them," said Drace, a 40-year veteran of the company. "But these guys were good, really good at being bad."

Facing what he thought was an imminent shutoff of electricity, Drace said he felt he had no choice but to act on the caller’s instructions to send $1,625 using a money transfer service called MoneyPak. Because of a glitch in the procedure, Drace was able to transfer only $625.

When Drace was finally able to get in contact with HECO, he discovered that he had fallen victim to a scam that utility officials say is becoming more and more prevalent on Oahu.

There have been about 150 such cases reported by HECO customers since April, although the actual number is probably higher because many of those who have been scammed may not have reported it, said HECO spokes­man Peter Rosegg. The frequency of reported cases has grown in recent months, and scammers are now using emails in addition to phone calls to carry out the con, he added.

The utility does not keep track of how many of those who were approached actually lost money. It’s also not clear whether it’s just one scammer or more. The calls generally come from toll-free numbers with an 866 prefix, according to Rosegg.

The cases involving HECO have been reported to both the Hono­lulu Police Department and the FBI, but no arrests have been made.

Businesses targeted by the scammers are often establishments that might have Chinese- or Spanish-speaking owners, according to HECO. The types of businesses being targeted include restaurants, saimin shops, liquor stores, barbershops, bars and minimarts.

When restaurants are targeted, the scammer usually calls during lunch or dinner hours in hopes the establishment will scramble to make the payment rather than lose power during mealtime, Rosegg said.

In most cases — including the episode with Young Laundry & Dry Cleaning — the scammer says a utility truck is in the area that can pick up the overdue payment within 45 minutes. About 30 minutes later the scammer calls back to say the truck was called to another job and that the customer needs to make the payment using the MoneyPak service.

MoneyPak cards, which can be purchased only with cash, are legitimate products when used for the right purposes. Scammers like them because they are more convenient than wiring money, and the transaction is untraceable. Once the scammers obtain the numbers on the back of the card, they can drain the funds immediately.

Rosegg said HECO would never cut off a customer’s service under the circumstances described by Drace. He urged any HECO customer who gets a similar call to hang up and call the utility’s customer service department at 548-7961. The number can also be called to report suspicious emails.

Recommended HECO bill payment methods include by U.S. mail, online through HECO’s website or in person at the utility’s customer service desks on Ward Avenue or the American Savings Bank building downtown. Payments also can be made at Foodland, Sack N Save, Walmart, Kmart, Times Supermarket and Safeway.

Drace said he hoped that by taking his story public he could prevent others from suffering the same fate. "I think there are a lot of people out there that are getting scammed and don’t even know it," Drace said.

HECO isn’t the only utility on Oahu that has been targeted by scammers.

The Board of Water Supply is warning customers of a telephone scam in which customers are contacted early in the evening with bogus collection calls.

The latest incident involved an early evening call to a Board of Water Supply customer in which the person claimed that a balance of about $100 for the water/sewer bill had to be paid immediately or else service would be shut off.

The customer asked to speak to a supervisor, who reportedly demanded credit card payment at that time and threatened service shutoff. The customer complied with the demand and provided the caller with a credit card number. When the customer checked the account balance the next day, there was no record of the payment.

The Board of Water Supply said that anyone receiving a similar phone call is encouraged to call the utility at 748-5030 to confirm the account balance first before making payment.

Hawaii Gas said it received numerous calls Friday from customers saying they got an email from Energy Billing System, notifying them that their energy bill is available to view online. The email lists a fake account number, charges, amount due and payment due date. Hawaii Gas does not currently have an option for customers to view their bill online. While no customers reported losing money, Hawaii Gas wants to let people know not to respond to the email or open attachments.

Hawaii Gas customers have also reported receiving bill statements from Pacific Gas & Electric Co. in Cali­for­nia as a potential scam. Hawaii Gas said customers who receive suspicious emails or bills should contact the Hawaii Gas customer service center at 535-5933.