Trump said Cruz knew about the ad, adding he started the latest fight between the two. Last week, Trump threatened to "spill the beans" on Cruz's wife in response to the ad featuring Melania Trump. He then shared a tweet featuring a photo of his wife next to a photo of Cruz's wife, stating, "A picture is worth a thousands words."

Cruz has denied knowing anything about the ad, and called it deplorable on Sunday.

But Trump said the super-PAC that produced the ad is "very friendly to Ted Cruz."

"He knew all about it, 100 percent," he said. "There's no way in a million years that super-PAC did that without his absolute knowledge."

Cruz campaign spokeswoman Catherine Frazier said the campaign did not buy the photo rights. "Of course we haven't and Trump knows it," she said in an email to The Hill. "But [it's] part and parcel for the sleazy, dishonest campaign he is running."

—Updated 9:43 p.m.