US President Donald Trump has taken to social media on Saturday to attack the "vandals" he claims are responsible for damaging the Lincoln Memorial Reflecting Pool in Washington DC, with a former Olympian among those arrested.

Trump's claimed on his preferred social channel, his own Truth Social, that federal authorities had made “multiple arrests” of people he claimed were vandalising the Reflecting Pool.

In the early hours of Sunday morning, Trump wrote online: "Many additional people have been arrested having to do with the disgraceful Vandalism of our beautiful Reflecting Pool.

"What they have damaged does not even include the earlier killing of a large amount of grass which was, by far, the least of it. They took some form of knife or blade, and put a 250-foot-long gash into the beautiful facade of what took so much work, competence, and money to build and complete.

"They also poured corrosive and destructive chemicals into the Pool."

The US President added that contractors told on Saturday that the Reflecting Pool will be need to be drained for repairs, but the work will be "done as quickly as possible", as he tries to explain why the USD$14-million-plus rehabilitation project he launched for the nation’s 250th anniversary has seemingly backfired.

Trump's claims come as a former Olympian was arrested for allegedly vandalising the pool. David Hearn, a three-time Olympic canoeist who competed for the United States, told the Washington Post that he was cycling past the monument on Friday when he said he stopped and noticed a piece of the pool’s liner floating in the water.

Hearn, 67, told the paper that he reached out and touched the detached piece of liner. Within moments, he was taken into custody by Park Police.

Now-viral video footage captured Hearn looking bewildered as he was confronted by members of the National Guard. He then can be seen being put into handcuffs by police.

“I didn’t vandalise anything,” Hearn said, as per The Washington Post. “I didn’t destroy or break or peel anything. By the time I realised what was going on, I was being put in handcuffs.

“I reached in there, and I was able to grab the end of that flapping piece, the already peeling piece. It was still attached to the bottom. I didn’t remove anything."

Hearn competed in the Whitewater Slalom Canoe on behalf of the US the 1992, 1996, and 2000 Olympic Games.

The former Olympian revealed that he was detained for almost five hours at a Park Police facility. He is scheduled to appear in front of a DC Superior Court on July 9.

The Olympian's arrest comes after earlier claims made by the US President claimed on Friday (June 19) that there had been "some real problems with vandalism at the beautiful Reflecting Pool".

"It’s a shame that the Radical Left Lunatics, most likely Dumocats, who have spent their lives trying to ruin our Country, are free to do so,' Trump wrote.

"Law Enforcement is actively investigating this situation, and will hopefully have it resolved soon."

The 47th US President also attacked a reporter amid the Reflecting Pool debacle, accusing "lightweight ABC Reporter Jonathan Karl" of sticking his hand in the pool and trying to rub the rubber off the surface.

His comments come after Karl reported for ABC News on Thursday that his team found the Reflecting Pool filled with gunk and green algae. Karl added that the multi-million dollar paint job also appeared to be falling apart.

Earlier this month, Trump announced on Truth Social that the restoration to the Reflecting Pool was complete, bragging that the renovation was "very complex, but powerful".

The President also said clean water had been added to the pool but, just weeks after Trump's triumphant announcement, algae growth turned the new water in the Reflecting Pool a stomach-churning green. Last week, crews were seen dumping hydrogen peroxide into the water in an attempt to curb further algae growth.

The US Department of the Interior, the state body that is overseeing the project, said in a media statement that "nanobubbler technology" had been installed to address the buildup of algae.

Trump has gone on to claim that the algae is 75 percent gone. The Reflecting Pool has plagued previous US administrations, as algae buildup has frequently prevented the water from properly reflecting the memorial as designed.