The Wall Street Journal, citing anonymous sources, reported on Monday that F.B.I. agents from the San Juan field office were investigating the contract, but such an investigation could not be confirmed.

The F.B.I. national office referred questions about the report to the Puerto Rico field office. A spokesman there, Carlos Osorio, said the agency could not confirm or deny the existence of an investigation.

“While Whitefish is not aware of any such investigation, Whitefish is committed to full cooperation with any inquiry or investigation,” the company said in a statement. “The procurement of the Prepa contract was at all times fully appropriate. Our focus continues to be on our work in Puerto Rico completing the work Prepa has tasked Whitefish to complete including the repair of the second major transmission line.”

A spokeswoman for the power authority said the agency had no information about an investigation, and therefore had no comment.

The governor’s office said it welcomed an inquiry.

“We have not received any information about the F.B.I. looking into the contract, but Governor Rosselló welcomes any investigation by the federal authorities and he has been clear: There should be an investigation on this matter, and if there is any wrongdoing, the persons responsible should be prosecuted to the full extent of the law,” Yennifer Álvarez, the governor’s spokeswoman, said. “That’s why the Governor has asked for investigations by the Comptroller of Puerto Rico and the Inspector General of the Department of Homeland Security, John Roth.”

In a phone interview, Ms. Farha, an independent expert reporting to the United Nations, said it was “very worrying” that she had not been able to obtain clarity on the number of people who were still homeless after the storm. She noted that estimates of the number of houses destroyed ranged from 30,000 to 90,000.