Denise Richards and Richie Sambora have split up - again.

The couple - who reunited last November after splitting in 2007, before going their separate ways again in January and reconciling last month - have ended their relationship following a huge row in Nashville, Tennessee, last week.

"It's over. They had an epic argument in Nashville and Denise told Richie she couldn't continue the relationship any longer," a source said.

Fellow guests at the Hermitage Hotel in Nashville - where the couple were staying ahead of Richie's planned presenting role at the CMT Awards - said they could hear "Sambora screaming obscenities at the top of his lungs" from their ninth-floor suite and he appeared drunk as he walked through the building.

"I was wondering what the problem was," one guest said.

Denise, 41, had been due to accompany Richie to the CMT Awards at the Bridgestone Arena, but walked the red carpet alone after the 52-year-old rocker pulled out at the last minute. It has been claimed that Richie initially told organizers he had to return to Los Angeles because of a personal problem with Ava, his 14-year-old daughter from his marriage to Heather Locklear, but he later told another official he was ill.