The US Justice Department on Friday dropped its case against a former Olympian accused of damaging the Lincoln Memorial Reflecting Pool, saying the hurried renovations ordered by President Donald Trump had been botched.

David Hearn, 67, had been charged with felony vandalism in federal court, which carried a potential sentence of 10 years in jail.

Federal prosecutor Jeanine Pirro had announced the charges in a high-profile press briefing earlier this month, saying witnesses had viewed Hearn “forcefully and violently” pulling up the pool’s new liner on June 19.

But in a court filing on Friday, Pirro said new revelations “undermine the evidentiary basis for the indictment,” and moved for dismissal.

She said that new documents indicate that the damage to the landmark “was the result of a botched installation and not vandalism as initially represented” by the Interior Department.

Trump had personally overseen the renovation of the Reflecting Pool, including the addition of an “American flag blue” liner.

It was one of several “beautification” projects around the US capital that Trump had ordered ahead of the July 4 celebration of America’s 250th anniversary.

The painting and sealing project was estimated to cost at least $14 million.

But problems soon arose, with the coating peeling off and algae turning the pool’s water a mucky green — setbacks Trump repeatedly blamed on vandals, without providing evidence.

Hearn, who competed in three Olympic Summer Games in canoeing, told US media he visited the refurbished pool after a long bike ride and noticed a piece of partially detached liner.

He reached into the water to see what it felt like, and as he prepared to leave, US Park Police arrested him.

“I didn’t vandalise anything,” Hearn told The Washington Post last month.

“I didn’t destroy or break or peel anything. By the time I realised what was going on, I was being put in handcuffs.”

His legal team had sought to have the case dismissed, arguing it represented a politicised justice system under Trump.

Lawyers Norm Eisen, Mary Dohrmann and Steve Levin said in a statement Friday that the case “should never have been brought.”

“Its dismissal today does not erase the abuse of government power in arresting and charging a patriotic American who did nothing wrong,” they said.

“The government’s approach was ready, fire, aim. The administration owes Mr Hearn an apology.”

Trump earlier threatened jail time for anyone seeking to damage one of his signature renovation projects.

“Please remember that there is a 10 year prison sentence for the destruction, or even the attempted destruction, of such things — Which will be fully enforced!” the president said in June.

Law enforcement for the National Park Service told AFP in June that five people were arrested for vandalism and five others were issued federal citations.