The Maine Public Utilities Commission has closed its summary investigation into potential rate impacts at Central Maine Power after a subcontractor withdrew his lawsuit last month containing allegations against CMP’s parent company, and a federal judge dismissed the case.

“The complaint has been dismissed without any evidence or testimony supporting the claims that the utility defendants intentionally overpaid for equipment and infrastructure to inflate (capital spending),” the PUC commissioners wrote in an order March 8. “Therefore, there is no purpose to continuing this investigation at the current time.”

The action comes roughly one month after a cybersecurity expert withdrew a federal lawsuit that accused Avangrid Inc. of bid rigging. Paulo Silva, chief executive officer of Security Limits Inc. of Pennsylvania, also had accused Avangrid of racketeering and buying unnecessary equipment in his November lawsuit in U.S. District Court in New York.

Avangrid has denied the allegations and filed a defamation lawsuit in New Mexico against Silva and his company.

Silva’s charges drew attention in Maine because of an allegation that Avangrid paid tens of millions of dollars to have structures erected in Maine and New York “to house the dust-gathering hardware that lacked any discernible purpose.” He also alleged that the company intentionally overpaid for equipment and infrastructure to inflate its capital spending so that, through the utility ratemaking process, there would be enhanced profits paid for by utility ratepayers.

The charges prompted Gov. Janet Mills to call for the PUC to investigate the matter. A handful of lawmakers that included CMP critics also pushed for a probe.

“Mainers deserve to know the truth behind these allegations, and it is the responsibility of the commission to determine the extent to which ratepayers may have been impacted by the impropriety alleged by the plaintiff of this case,” they said in a letter to the PUC.

The agency subsequently directed CMP to submit a detailed report noting any costs described in the complaint that are currently being recovered in its rates or may be recovered in future rates.

On Jan. 18, CMP submitted its report. CMP stated that the spending referred to in Security Limits’ complaint is a comprehensive security project designed to reduce the company’s risk exposure, to enhance power grid security, and to ensure compliance with the regulatory obligations regarding critical infrastructure protection.

On Feb. 9, the district court issued a notice of dismissal. CMP stated at the time that Security Limits did not provide any evidence or sworn testimony to support its case and did not answer or dispute charges of defamation and extortion.

CMP then requested that the PUC docket be formally closed.

The PUC said it would reopen the investigation if any evidence of inflated spending is produced.