BEIJING - The top official of the Palace Museum in Beijing's Forbidden City admitted on Friday that human error led to the damage of at least three antiques.

Museum director Zheng Xinmiao said that careless staff members damaged three relics that date back to the Qing Dynasty (1644-1911). Two ritual implements suffered damage in May 2004, and a flower receptacle was damaged in 2009, Zheng said.

On August 2, the whistle-blower "Longcan" first made the accidents public through a blog, stating that the museum had covered up four major accidents to relics.

On July 31, the museum reported that a researcher had accidently damaged a rare thousand-year porcelain dish.

The Palace Museum has been under fire since May when exhibition pieces on loan from a Hong Kong-based museum were stolen in the palace complex.

Whistle-blowers also accuse the museum of running an exclusive club in one of its palaces and paying hush money to insiders who threaten to expose ticket scandals.

Zheng admitted there are "management loopholes" and blamed the museum's "lax supervision" of its commercial partner, Forbidden City Palace Cultural Development Co, as the cause of business activities in the palace.

Zheng said the museum has been offering monetary rewards for those who come forward with information that leads to the arrest of employees found cheating the museum out of ticket revenue.

In an effort to defuse public anger, Zheng has vowed to promote protection awareness among museum staff, upgrade its security system, and fully gauge potential risks in protection and exhibition activities.

Zheng also promised more transparency and engagement with the public on a regular basis.