An NYPD officer who found the body of a Manhattan man used the victim’s credit card number to buy herself a pricey diamond ring, authorities said Tuesday.

Officer Ymmacula Pierre, 30, was charged with possession of stolen property, ID theft, attempted grand larceny and official misconduct for allegedly going to a jewelry store’s website and using the dead man’s Citibank MasterCard number to buy bling valued at more than $3,200.

Days before the purchase, on July 14, 2014, Pierre and her partner responded to a call from a relative worried that 65-year-old architect Kenneth Sanden, who had several health problems, had not shown up for work.

Arriving at Sanden’s East 14th Street apartment, they found him dead, according to court records.

Pierre vouchered some of Sanden’s possessions, including the credit card, officials said. Two days later, the number was used to make an unauthorized online purchase of a diamond ring from Zales.com for $3,282.58. Sanden’s niece was notified of possible credit-card fraud and alerted the vendor before the ring was delivered.

“He was taken advantage of,” the niece told The Post, noting that she worked with police to track down the diamond’s buyer.

Zales had already shipped the item, but the store reached out to FedEx, which halted the delivery.

The delivery address, and the IP address of the computer used to make the purchase, matched the address of Pierre’s boyfriend, whom she had listed as a reference on her NYPD application.

Pierre had also allegedly used the computer at her boyfriend’s place to access Sanden’s email account.

“Because police officers take an oath to protect and serve, they are held to a higher standard of behavior in the course of their duties,” said Manhattan DA Cyrus Vance Jr.

“No grieving relative should have to worry about alleged theft and misconduct by a uniformed officer in the aftermath of a loved one’s passing.”

Pierre, a three-year veteran, pleaded not guilty at her arraignment Monday. She was released on her own recognizance.

She could not be reached for comment.