LOS ANGELES (AP) — Robin Thicke's attorney says the estate of Marvin Gaye exploited the singer's "moment of personal vulnerability" in an attempt to prove that the hit "Blurred Lines" was a ripoff of a Gaye hit.

The estate sued Pharrell Williams and Thicke over the song last year.

In a deposition, obtained Tuesday by The Associated Press, Thicke says Pharrell Williams did much of the writing on the Grammy-nominated song and says, "I was just lucky enough to be there when he wrote it."

Thicke also says he was high on a mix of prescription drugs and alcohol during the writing of the song and in interviews following its release.

"In fact, I was quite surprised when I read them back sometimes," he said about the interviews.

Attorney Howard King said lawyers for the Gaye estate are just trying to prop up their lawsuit that says the 2013 international hit was stolen by writers, including Thicke and Williams, and that it ripped off "Got to Give It Up."

"Robin's moment of personal vulnerability is being exploited in the hope of diverting attention from the obvious weakness of their legal claim," King said in an email Monday night from Thicke's publicist.

Attorneys for the Gaye family did not immediately return messages sent Tuesday night.

April depositions by Thicke and Williams in the case were unsealed Monday, revealing a different story than the one the two men were giving the public during interviews last year about the song.

"The record would have happened with or without me," Thicke said in the deposition. "I was just lucky enough to be there when he wrote it."

He also described his daily routine for attorneys.

"Every day I woke up, I'd take a Vicodin to start the day," Thicke said. "And then I'd fill up a water bottle with vodka and drink it before and during my interviews."

Thicke said he began to claim more credit for the song after it became an inescapable hit. He said in the deposition he began to take more credit than he was due in interviews because he felt disappointed that his biggest hit had been written by someone else.