The wreckage of a US aircraft carrier credited with helping save Australia from possible Japanese invasion during World War II has been found off the Queensland coast.

Key points: USS Lexington went down on May 8, 1942

USS Lexington went down on May 8, 1942 Its wreckage was discovered 800km off the Queensland coast on Sunday

Its wreckage was discovered 800km off the Queensland coast on Sunday Search team funded by US billionaire Paul Allen found the aircraft carrier

In May 1942, the USS Lexington, along with 216 of its crew and 35 aircraft, was lost during the Battle of the Coral Sea.

Seventy-six years later, a search led by US billionaire Paul Allen has now located the wreckage around 800 kilometres off the coast of Queensland.

Finding the USS Lexington was on Paul Allen's "priority list" in terms of subsea operations. ( Supplied: Paul Allen )

The USS Lexington's resting place — or at least the rough location — had been known for some time, but this expedition captured the first photographs of the warship since it went down in WWII.

Video from Research Vessel Petrel captures the moment the crew noticed the iconic vessel's nameplate lurking beneath layers of barnacles and debris at the bottom of the ocean.

"Right there, Lexington." "Where?" "Right there." "I can't see where you're pointing." "L-E-X…" "Oh yeah, stamped into the steelwork." "If there was ever any question…"

Team leader Mr Allen, who co-founded Microsoft with Bill Gates, has invested heavily in under-sea exploration.

Who is Paul Allen? Paul Allen co-founded Microsoft with Bill Gates in 1975

Paul Allen co-founded Microsoft with Bill Gates in 1975 He's now estimated to be worth $21.8 billion

He's now estimated to be worth $21.8 billion He's pledged to give away the majority of his fortune, and has so far donated $2 billion to various causes

He's pledged to give away the majority of his fortune, and has so far donated $2 billion to various causes He's heavily invested in technology, science, conservation and exploration

He's heavily invested in technology, science, conservation and exploration It was his research vessel that discovered the wreckage of USS Indianapolis — an American ship that sank in WWII when it was torpedoed by a Japanese submarine — in 2017

It was his research vessel that discovered the wreckage of USS Indianapolis — an American ship that sank in WWII when it was torpedoed by a Japanese submarine — in 2017 He's also heavily invested in sport — he owns the NBA's Portland Trail Blazers, the NFL's Seattle Seahawks, and has a stake in the Seattle Sounders soccer team

His research vessel has discovered several other wrecks including that of another warship, the USS Indianapolis, last year.

"To pay tribute to the USS Lexington and the brave men that served on her is an honour," he said in a statement.

"As Americans, all of us owe a debt of gratitude to everyone who served and who continue to serve our country for their courage, persistence and sacrifice."

How 'Lady Lex' went down

USS Lexington, nicknamed "Lady Lex", was originally designed as a battlecruiser but was converted into an early aircraft carrier for the US Navy.

Lady Lex took part in the Battle of the Coral Sea along and was credited with helping stop the Japanese advance in the Pacific during World War II.

In the months before the Lexington went down, Japan had attacked the US battleship fleet at Pearl Harbour, and it was feared an invasion of Australia was imminent.

Japanese forces had formed a solid defensive perimeter and were looking for ways to strengthen their gain and cut the lines of communication between Australia and the west coast of the US.

After a days-long stand-off between Japanese and Allied forces in the Coral Sea, the Lexington was defeated on May 8.

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Along with the USS Yorktown, Lady Lex had launched a number of bombers, torpedo bombers and fighters, but the combat air patrol did not have enough fuel to intercept attacks from Japanese bombers.

The Lexington, larger and less manoeuvrable than the Yorktown, was hit on both sides by multiple torpedoes and bombs.

USS Lexington under attack in the Coral Sea, on May 8, 1942 during the Battle of the Coral Sea. ( Supplied: US Naval Historical Centre (# NH 95579) )

She managed to survive and continue deploying aircraft for several hours.

And it was not until a secondary explosion causing uncontrolled fires that Lady Lex finally went down.

The carrier was torpedoed and sunk by 8:00pm, and 216 crew were lost.

USS Lexington went down after it was torpedoed by Japanese forces in the Battle of the Coral Sea. ( Supplied: Australian War Memorial P02018.098 )

US Pacific Commander Admiral Harry Harris, who is also President Donald Trump's nominee for US ambassador to Australia, said he was elated at the find.

"As the son of a survivor of the USS Lexington, I offer my congratulations to Paul Allen and the expedition crew of Research Vessel Petrel for locating the 'Lady Lex'," he said on Twitter.

"Our Navy's strength comes from those who have gone before. This is our heritage. Our Navy's strength comes from those who serve now. This is who we are.

"No-one should doubt that today's warriors are ready to fight tonight and win."

Amongst the wreckage of the USS Lexington, several recognisable aircraft were found, including seven Douglas TBD-1 Devastators and a number of Grumman F4F-3 Wildcats.