Maine's largest power company is under investigation after more than 1,000 customers complained to state regulators about spiking electric bills.

The Public Utilities Commission voted unanimously Tuesday morning to launch a management audit into Central Maine Power's billing practices.

"People should have trust and confidence in a bill that they receive from their utility," said PUC Chairman Mark Vannoy. "If that trust and confidence is eroded, the commission needs to be looking into it."

Hundreds of customers have contacted the PUC and taken to social media, complaining that recent electric bills are more than double what they usually pay.

Linda Flagg of Jay is one of them.

"Something is going on here, and I don't trust my billing," she said.

She said the price increase does not seem to match any change in electricity use, and suspects there is an issue with CMP's smart meter system.

"What other explanation is there?" she asked.

The power company had been pointing to severe weather. In October, a strong wind storm knocked out power to hundreds of thousands of Mainers. Then a brutally cold snap during the winter forced many homeowners to turn up their heat.

But some customers aren't buying that explanation. They are praising the PUC for launching the investigation, but wish it was happening faster.

"What have they been doing the past month?" said Flagg. "What have they been doing to protect the consumer?"

Maine's Public Adovcate, Barry Hobbins, said CMP customers disputing their bills should contact the PUC's consumer assistance division at 800-452-4699. Registering a complaint with the PUC could help prevent a customer from having his or her electricity shut off.

Hobbins said the volume of the complaints has been unprecedented.

"If it weren't for the rate-paying public's complaints, this [vote to investigate] would not have happened," said Hobbins.

"We welcome the PUC’s assistance and look forward to working together to ensure that our customers are being billed fairly and accurately," Central Maine Power President and CEO Doug Herling said in a statement. "At the same time, we are conducting our own comprehensive review of the complaints to determine what the underlying causes were for the increases. Any detected errors will be fixed and those customers will be made whole."

The PUC's management audit is expected to take several months to complete.