Pop singer Beyonce Knowles should not have been allowed to perform a scantily-clad dance on the tomb of former United States President Ulysses S Grant, a historical group has said.
Beyonce took part in the annual Macy's Fourth of July celebrations
The star danced in a "patently inappropriate" way on the steps to the tomb during a nationally-televised 4 July concert, according to Frank Scaturro, president of the Grant Monument Association.
The Destiny's Child chart-topper used "lascivious choreography" and her backing dancers were barely dressed, Mr Scaturro said in a letter to NBC, which filmed the performance.
Her latest single, Crazy In Love, is currently number one in the UK and US.
And her album held onto the top spot in the UK on Sunday but was knocked off the summit in the US by Ashanti last week.
In his letter, Mr Scaturro wrote: "At that location, a certain decorum should have been observed from which popular entertainers are not exempt."
The letter also went to the Secretary of the Interior, Gale Norton, and National Park Service director Fran Mainella.
Ulysses S Grant was a Civil War hero who became the 18th president, between 1869-77.
His tomb, erected as a national monument in 1897, is in New York. The concert was part of the annual Macy's Fourth of July celebrations.
Also performing were American Idol winner Kelly Clarkson plus Sheryl Crow and John Mellencamp.
Ulysses Grant Dietz, the great-great-grandson of Ulysses S Grant, said he did not object to most live performances, as long as the tomb was looked after.
But organisers could have been more thoughtful, he added.
"If they're doing a Fourth of July celebration and they're doing it at a grave of a president, maybe they should look a little more closely at what the performances are."
NBC and Beyonce were not available for comment and a National Park Service spokesman did not want to comment because he had not seen the letter.