Central Maine Power Co. say an internal audit triggered by more than 1,500 customer complaints has so far found no problem with the company’s systems that can explain abnormally high electric bills.

The company has reviewed about 25 percent of the 1,580 complaints of excessively high bills it received this winter, said President and CEO Doug Herling on a conference call with reporters Friday morning.

Auditors have so far found no anomalies with new billing software or its smart meter network to explain bills that for some customers were two and three times the norm, Herling said.

“We have done our investigation, at this point in time we have not found anything about our system or smart meters that would artificially increase customer’s usage,” he said.

The company is doing the audit as fast as possible and will report any new findings, Herling added.

“If anything were to be found, we would make that right to the customer and make sure any charges were appropriate,” Herling said.

The Maine Public Utilities Commission this winter received hundreds of complaints from CMP customers who reported sudden spikes in their electric bills.

The extreme bills occurred during a severe cold snap that engulfed the state following Christmas and extending through January.

An initial PUC inquiry into the bills was inconclusive. Regulators are now hiring a consultant to perform a more intensive audit.

“We stand ready to assist the PUC to do a full, completely comprehensive review of our systems,” Herling said. “We welcome this audit, it is an independent audit, we are confident with what it will show and that it will give customers confidence that our systems are working.”

CMP has tested 1,600 meters at the requested of customers since January, four times the number it tested all last year, Herling said Friday. Only one meter was found to be working improperly, and it was an older mechanical model, not a new smart meter, he added.

“We feel confident the smart meters are working properly,” Herling said. “We have not found any issues that would impact the bill negatively from smart meters.”

Central Maine Power has been reaching out to customers to explain and resolve high bills and has brought in extra staff to call customers after business hours and on weekends.

Of the customers CMP has contacted to discuss the complaint, about 61 percent, or 250, said they were satisfied and did not want to pursue their case further with the PUC, according to Shobana Lemoine, director of corporate communications for Avangrid, CMP’s parent company.

The company insists that almost a month of sub-freezing temperatures, combined with an 18 percent hike in the standard electric rate were the likely cause for high power bills.

Customers of power companies in 22 other U.S. states stretching from Michigan to Louisiana and Texas reported similar complaints of huge power bills after the cold snap four months ago, according to a recent Maine Sunday Telegram analysis of national news coverage.

Herling, on Friday, said he couldn’t fully explain why more CMP customers have complained compared to other power companies. The cold weather was an issue that affected everyone, he said.

“It seems in Maine it is an issue that has reached a higher public awareness than in other areas,” Herling said.

This story will be updated.