The body of a man discovered on the property where a woman was found "chained up like a dog" has been identified as the woman's boyfriend, Charles Carver.

The 32-year-old man's body was discovered in a shallow grave on the South Carolina property on 4 November, one day after his girlfriend was found chained up in a storage container, and was identified as Carver on 5 November.

Carver and his girlfriend are believed to have been missing since around 31 August this year, and authorities are now working to establish how long ago Carver was killed.

When the couple disappeared, their case garnered press attention after Carver's Facebook account suddenly became active, with one post stating the couple had got married, and others sharing violent and disturbing quotes.

His family reportedly believe someone had hacked his account and posted fake messages from him following his disappearance.

The woman who was rescued from a container was found on the land of registered sex offender Todd Christopher Kohlhepp, 45, and allegedly told police her captor had shot her boyfriend dead.

Kohlkepp was arrested and charged with kidnapping after the women was found by police, who had been searching the area after receiving a top-off about a sex crime.

Sheriff Chuck Wright told reporters that the deputies found the 30-year-old woman "chained inside the container like a dog" when she began pounding on the walls.

A friend of the woman, Daniel Herren, told the Associated Press of her kidnapper: "He never took the chain off of her, but he was taking her around, let her get, not so much exercise, but let her walk around some. It didn't sound like it was every day. It was kind of sporadic."

Kolhkepp is set to remain in custody until his first court hearing on 19 January.

Todd Kohlhepp
Todd Kohlhepp, a registered sex offender who has been arrested in connection with the kidnapping of Kala Brown and Charles David Carver is shown in this booking photo provided in Spartanburg, South Carolina, 3 November 2016. Photo courtesy of Spartanburg County Detention Center/Handout via REUTERS