TAMPA, Fla. (WFLA) — Deputies found what they believe to be human remains Friday morning on the same property where a Florida couple was tied up and held captive, according to the Clay County sheriff.

Sheriff Michelle Cook announced the discovery during a news conference Friday, according to NBC affiliate WTLV.

This is another development in what originally began as a home invasion case Monday night after the kidnapper, 46-year-old Aubrey Lumpkin, called 911 to confess to the crime.

“I’m a piece of s—,” Lumpkin was heard saying on the 911 call. “I need medical attention out here for this elderly couple. I’m turning myself in.”

This led deputies to the home in Green Cove Springs where they found the couple restrained by duct tape. The couple was malnourished, dehydrated, and suffered from infections, according to authorities.

Cook said that during their investigation, Lumpkin had repeatedly said he buried someone in the area.

“We’ve uncovered what could potentially be human remains,” Cook told WTLV. “I do not know how long those remains have been there, other than they have been there for a while.” 

The remains have yet to be identified.

WTLV reported that the victims’ relatives said that Lumpkin used to live in a separate home on the same property with one of the couple’s daughters. However, she had not been heard from since she left the home, and there has been no connection made yet.

WTLV also said that Lumpkin mentioned an accomplice, but it is not known where he acted alone.

“Mr. Lumpkin made a lot of statements that night, and we’re taking every statement he made and running it down,” Cook said.