Hot on the heels of their embarrassing sex-tape scandal, Grey’s Anatomy Eric Dane and wife Rebecca Gayheart  caught using cocaine, claims an eyewitness.

Only days after the video of the couple romping naked with a former Miss Teen USA was leaked on the Internet, a source alleged that he had seen the couple snorting cocaine at a Hollywood party.

The latest harrowing scandal also follows The ENQUIRER’s publication of a shocking exclusive photo of Rebecca – showing the former Beverly Hills, 90210 star naked in a bathtub holding a crack pipe.

The Hollywood Hills cocaine party took place late last year, according to the source.

Eric, 36 – who plays Dr. Mark "McSteamy" Sloan – arrived with 38-year-old Rebecca, according to the eyewitness, who passed a lie detector test about the claim.

"I think Eric and Rebecca were there to get high. It didn’t take long before she asked where the coke was. They went into another room and started snorting lines of cocaine. I watched them do it.

"They arrived in the afternoon and stayed well into the evening.

"Rebecca used to date one of the guys at the house. I’m sure she knew he had major drug connections."

The party took place up a winding road at a hideaway mansion that is notorious for the availability of a wide array of different drugs, said the source.

"Put it this way, if you’re at this house, you’re there to get high.

"I saw Rebecca snort lines a couple of times – and Eric at least once.

"Lots of people were in and out of that home that night for the same reason – drugs."

Eric and Rebecca, who have no children, have been active members of Alcoholics Anonymous for years, and although they have relapsed in the past, they have always managed to clean up their act, say friends.

"They aren’t that different from many showbiz people who get caught up in an industry that glamorizes drugs, sex and fast times," said a pal.

"Eric’s and Rebecca’s lapse WAS huge – and it may cost them dearly."