Terracotta Warriors which guarded the tomb of China's First Emperor, Qin Shi Huang, on loan from China are displayed in The World Museum, Liverpool, Britain February 6, 2017. (Xinhua/REUTERS)

WASHINGTON, Feb. 17 (Xinhua) -- Federal authorities have said that a U.S. man stole late last year a thumb of a Chinese terracotta warrior statue being displayed at a Philadelphia museum in state of Pennsylvania.

According to an arrest affidavit filed Friday, Michael Rohana, a 24-year-old man from state of Delaware, was attending a party held at the Franklin Institute on Dec. 21 last year when he made his way into the museum's special exhibit "Terracotta Warriors of the First Emperor."

The FBI said that Rohana used a cellular telephone as a flashlight, looked at various exhibits displayed in the then-closed showroom, stepped up onto a platform supporting one of the statues, and took a selfie with it.

Rohana, according to the affidavit, put his hand on the left hand of the statue, appeared to break something off from the Calvaryman's left hand and put it in his pocket, and then left.

Museum staff noted the missing thumb on Jan. 8 and a special agent from the FBI's Art Crime Team tracked down Rohana days later and showed up at home in Bear, Delaware to question him about the finger, authorities said.

In front of his father, Rohana admitted it that he had stashed the thumb in his desk drawer.

A U.S. attorney has decided to charge him with theft of a major artwork from a museum, concealment of major artwork stolen from a museum, and interstate transportation of stolen property.

He was arrested and released on a 15,000-USD bail, on the condition that he hand over his passport, consent to drug testing, and refrain from leaving the country before trail.

It was not immediately clear whether he had retained a lawyer.

A spokeswoman for the museum said that the statue will be repaired, adding that a security contractor did not follow standard procedures the night of the alleged theft.

The statue that temporarily lost its left thumb, called the Cavalryman, dates back to 210 and 209 B.C. It is one of 10 elegant Chinese Terracotta warrior statues currently on display at the Franklin Institute. The special exhibit will run through March 4th.