Puerto Rico has acknowledged that Hurricane Maria killed 1,427 people in the US territory, not 64 as it has previously reported.

The latest figure was in a draft report for US Congress, requesting $139bn (£108bn) in recovery funds.

A government spokesperson acknowledged the latest number as a “realistic estimate” but said that the death toll had not been officially changed, as the authorities were awaiting the results of a study by George Washington University.

“We don’t want to say it out loud or publicise it as an official number… until we see the study and have the accuracy,” Pedro Cerame from the island’s Federal Affairs Administration told the Times.

Researchers from Harvard University said interviews conducted in Puerto Rico suggested a 60% increase in mortality in the three months after the storm.