Explosive new documents show the US government knew a weather map used by Donald Trump was doctored, despite publicly defending the president’s false claims about a hurricane striking Alabama.

In September last year, Mr Trump repeatedly claimed wrongly that Alabama would “most likely” be struck by Hurricane Dorian, a category five storm which devastated the Bahamas.

After being rebutted by experts, Mr Trump doubled down by showing off a doctored National Hurricane Center (NHC) map, which featured the projected path of Dorian with an additional Sharpie-drawn line around a corner of Alabama.

The National Oceanic and Atmospheric Administration (NOAA) leadership later backed Mr Trump against its own scientists when it released an unattributed statement defending the president’s claims and criticising a National Weather Service (NWS) tweet which said Alabama would “NOT see any impacts from the hurricane”.

NOAA staff were also warned against contradicting the president and told not to “provide any opinion about the issue".

"Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Show all 15 1 /15 "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures A road is flooded during the passing of Hurricane Dorian in Freeport, Grand Bahama. AP "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Hurricane Dorian's eye taken by Nasa astronaut Nick Hague, from aboard the International Space Station. The station orbits more than 200 miles above the Earth. Hurricane Dorian, which made landfall on the Bahamas as category 5 and now reclassified as category 4, is expected to continue on its projected path towards the Florida coast. Nasa/EPA "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Buildings damaged by Hurricane Dorian are swept by deep floodwater in the Abaco Islands in The Bahamas. Latrae Rahming "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Tropical Storm Dorian as it approached the Bahamas. NOAA/AFP/Getty "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Strong winds blow the tops of trees while whisking up water from the surface of a canal that leads to the sea in Freeport, Grand Bahama AP "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures A woman walks in a flooded street after the effects of Hurricane Dorian arrived in Nassau, Bahamas. REUTERS "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Uprooted trees, fallen power lines and debris scatter a road as Hurricane Dorian sweeps through Marsh Harbour in The Bahamas Ramond A King via Reuters "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Buildings damaged by Hurricane Dorian are swept by deep floodwater in the Abaco Islands in The Bahamas Latrae Rahming "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures A building is strewn with debris after its roof was torn off by Hurricane Dorian in the Abaco Islands in The Bahamas Latrae Rahming "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Uprooted trees, fallen power lines and debris scatter a road as Hurricane Dorian sweeps through Marsh Harbour in The Bahamas Ramond A King via Reuters "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Hurricane Dorian is pictured from a plane flying inside the eye of the storm Garrett Black/US Air Force "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Inmates from a Florida jail fill sandbags to hand out to residents ahead of Hurricane Dorian in Cocoa, Florida on September 1 EPA "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Residents stock up at Wal-Mart in preparation for Hurricane Dorian in Orlando, Florida Getty "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures A shop is boarded-up ahead of Hurricane Dorian in Cocoa, Florida on September 1 Reuters "Huge damage" as record Hurricane Dorian hits Bahamas: In pictures Waves batter a pier in Marsh Harbour in The Bahamas on September 1e Mark Hall vie Reuters

But a trove of emails requested by Buzzfeed and released by NOAA late on Friday shows the true extent of the anger and confusion among scientists at the response to Mr Trump’s false claims.

“I find it unconscionable that an anonymous voice inside of NOAA would be found to castigate a dutiful, correct, and loyal NWS Forecaster who spoke the truth,” NOAA’s acting chief scientist Craig McLean wrote in an email to leading officials on 7 September.

“What concerns me most is that this Administration is eroding the public trust in NOAA for an apparent political recovery from an ill timed and imprecise comment from the President. I hope that NOAA's trust in the public eye will outlast this Administration.”

(Getty Images)

He added: “Our employees need to know that we stand for science, not politically motivated apologies.”

Gary Shigenaka, a senior biologist at NOAA, asked the agency’s acting secretary of commerce Neil Jacobs to “address this crisis in moral leadership” and to reassure employees they were not “mere pawns in an absurd game”.

He added: “Please do not allow the science and support that we perform on behalf of the American public to be tossed into the trash heap by political expediencies. Please support and stand with us.”

Other emails confirmed the map used by Mr Trump to defend his assertions had been doctored.

“How do you want to handle this one? Looks like someone at the WH drew with a marker on the image of our official forecast,” Scott Smullen, deputy director of NOAA communications, said in an email to colleagues.

Under an email with the subject line, “Tweet shows POTUS altering NHC map’, public affairs specialist at the NOAA, Jerry Slaff told Mr Smullen the map “shows a sharpie extension of cone to include Alabama”.

“Yes, that was doctored,” Corey Pieper, an official in the NWS communications division, said to public affairs official Susan Buchanan.

Mr Trump claimed at the time he did not know who had doctored the map – Bloomberg reported he did it – before claiming “all” models gave Alabama a “95 per cent chance probability” of being hit.