Transcript for Robin Thicke Denies Creating Most of 'Blurred Lines'
And now to the shock scandal revelations from robin Thicke, the singer give scandal a wild deposition in his legal battle with Marvin Gaye's family, saying he didn't rip off the megahit for blurred lines. And he says he was high on drugs and alcohol. We have the story. Reporter: The song of summer, 2013. 50 million sales and an infectious hook. Now in a sensational deposition, robin Thicke claims he didn't really write blurred lines with pharell Williams. He claims burred vision. I was high and drunk in every interview last year. And both sides file scandal lawsuits about whether "Blurred lines" is a rip off of Gaye's 1977 hit, KWOT got to give it up." One of my favorites of all time is got to give it up. We tried to get a groove going. And wrote it in half an hour. Reporter: That VH1 interview was a lie, he said under oath. He says not only was he high on pain killers and drunk when he recorded "Blurred lines" in the studio, he was during interviews like that one. I do generally remember trying to sell the public on the fact that "Blurred lines" was any idea in some way. He looked like the next big super star. But the fact he didn't actually write his biggest song. What to point to now? Reporter: He claimed he was now off the painkillers. And the song, it became a huge hit, and pharrell had the beat and wrote almost every part of the song. Williams claims the song is held together by robin Thicke's voice. And the zpout over whether it's really a Marvin Gaye ripoff is due in court February next year. Nick watt, ABC news, los Angeles. And bring in Dan Abrams to weigh in on this. Before that, read a statement from robin Thicke's lawyer. Robin's moment of personal vulnerability is being exploited, and the obvious weakness of the claim. That is the claim of Marvin Gaye's family. Had to know this was going to be public. They had to know this statement was going to get out. And on the one hand, it's terrible for robin Thicke. He's saying I didn't write by miggest song ever. Now admit scandal that. And as a legal matter, it's important. He was out there in numerous interviews saying Marvin Gaye inspired me. We cranked out this song in half an hour, hour and a half, whatever the amount of time. That's really problematic for his case. He's saying he was on drugs when he said it, and he says I didn't write the song anyway. Ignore what I said. Think about how damage scandal that is, the deposition. We were talking about on the set, sample scandal. What's that? That's expected, and is there a substantial similarity, and most important, was the second song transformative? Did it fundamentally change what the first one had as inspiration? You can't copy it. You can't just knock it off. You have to do something that changes it. Makes it so much different that the new song is a fundamentally different piece. As you can tell, it's a blurred line. It is. Nicely done, Dan. It must be something about that chair. All right. Thank you, Dan. Thanks.
This transcript has been automatically generated and may not be 100% accurate.