None of the stars at Radio City Music Hall last week to raise money for the Martin Luther King Jr. National Memorial mentioned the quarrel that has been bubbling up over plans for the towering three-story monument in Washington.

For months now critics have been grumbling about the selection of Lei Yixin, a Chinese sculptor — rather than an African-American — to carve a stone statue of Dr. King on a four-acre plot between the Lincoln and Jefferson Memorials. Then last week Harry Wu, a prominent human-rights activist who spent 19 years in a Chinese prison, joined the fray, complaining that Mr. Lei has made statues of Mao. “How can you make statues for Mao Zedong?” he said in a telephone interview from Virginia. “He’s a butcher.”