WASHINGTON (REUTERS) - Hurricane Maria, the most powerful storm to strike Puerto Rico in nearly 90 years, is estimated to account for nearly 3,000 deaths, far more than the official toll of 64, according to a study commissioned by the island's government and released on Tuesday (Aug 28).

The report found that 2,975 deaths could be attributed directly or indirectly to Maria from the time it struck in September 2017 to mid-February of this year, based on comparisons between predicted mortality under normal circumstances and deaths documented after the storm.

The study, conducted by George Washington University's Milken Institute School of Public Health, also found that the risk of death from the hurricane was substantially higher for the poor and elderly men.

The report was conducted in collaboration with the University of Puerto Rico Graduate School of Public Health and was commissioned by Puerto Rico Governor Ricardo Rossello.

A previous study from a Harvard University-led research team released in May estimated that 4,645 lives were lost from Maria on the Caribbean island, and a Pennsylvania State University study put the number at 1,085.

The emergency response to the storm became highly politicised as the Trump administration was criticised as being slow to recognise the gravity of the devastation and too sluggish in providing disaster relief to Puerto Rico, a US territory of more than three million residents.

The storm made landfall on Puerto Rico with winds close to 241kmh on Sept 17 and plowed a path of destruction across the island, causing property damage estimated at US$90 billion (S$122 billion) and leaving much of the island without electricity for months.