Todd Kohlhepp has shown officers the graves of victims on his property
A man held after a woman was found chained up in a metal container has admitted to killing at least seven people, say US police.
Investigators said Todd Kohlhepp, a 45-year-old registered sex offender, had confessed to the murder of four people at a motorcycle garage in 2003.
He had also shown officers the graves of two other victims on his sprawling 100-acre property in rural South Carolina.
These were in addition to the body found on Friday at the site, which has been confirmed as that of 32-year-old Charles Carver, the boyfriend of the woman held captive for weeks inside a locked shipping container.
Following her rescue last Thursday, Kala Brown (30) told police she had seen the suspect shoot Mr Carver.
The pair had been missing since August.
The coroner said Mr Carver died of multiple gunshot wounds to the upper part of his body.
He was working with an anthropologist to estimate how long the victim been buried in the shallow grave.
Spartanburg County Sheriff Chuck Wright has said it was possible more bodies will be found at the property.
He had previously revealed Ms Brown and Kohlhepp knew each other and that her abduction was "not a random act".
A tip-off had led police to the property and her discovery.
Sheriff Wright said of solving the 2003 cold case killings: "God answered our prayers."