A DAY AFTER he was widely rebuked for mocking a reporter with a physical disability, business mogul and reality TV star Donald Trump yesterday denied that he had done so and accused the reporter of "using his disability to grandstand."

Trump also demanded an apology from the reporter's employer, the New York Times, which earlier in the week issued a statement condemning Trump for ridiculing "the appearance of one of our reporters."

The incident occurred Tuesday at a rally in South Carolina, as Trump was defending his recent claim that he had witnessed thousands of Muslims cheering in New Jersey on Sept. 11, 2001, as the World Trade Center towers collapsed. On stage, Trump berated Times investigative reporter Serge Kovaleski for his recent recollection of an article he wrote a few days after the attacks, which Trump has been citing to defend his claim.

Trump appeared to mock Kovaleski's physical condition; the reporter has arthrogryposis, which visibly limits flexibility in his arms.

"Now, the poor guy - you've got to see this guy, 'Ah, I don't know what I said! I don't remember!' " Trump said as he jerked his arms in front of his body.

Trump's assertions about Muslims celebrating in 2001 have been fact-checked and discredited by law enforcement and government officials who were in New Jersey in the days and weeks after the terrorist attacks.

Trump has defended his recollections by citing a 2001 article by Kovaleski, who worked for the Washington Post at the time and wrote that "authorities detained and questioned a number of people who were allegedly seen celebrating the attacks and holding tailgate-style parties on rooftops while they watched the devastation on the other side of the river."

Those allegations were never corroborated but have persisted in online rumors in the 14 years since the attacks. In an interview on CNN this week, Kovaleski said he did not recall "anyone saying there were thousands, or even hundreds, of people celebrating."

That is the statement that apparently drew Trump's ire.

Kovaleski frequently covered Trump while reporting for the New York Daily News between 1987 and 1993. In a statement yesterday, Trump adamantly denied that his comments or gestures were meant to mock Kovaleski. He also denied remembering Kovaleski at all - "despite having one of the all-time great memories."