Donald Trump Threatens to 'Spill the Beans' on Cruz's Wife After Racy Photo of Melania Trump Used in Ad

— -- GOP frontrunner Donald Trump has set his sights on his main Republican rival, Ted Cruz, threatening in a late night tweet to "spill the beans" on Cruz's wife, Heidi.

The tweet comes on the heels of a new anti-Trump Super PAC, Make America Awesome, releasing a Trump attack ad that features a racy image of the billionaire's wife, Melania, from her past modeling days.

The digital ad has been running in Utah and Arizona for the last several days, according to the group. The ad targets the conservative voting bloc of female Mormon voters and ran along with two other anti-Trump ads targeting both male and female Mormon voters.

Trump's campaign has not responded to requests for comment about what the candidate was referring to.

In a tweet, Ted Cruz, said that the ad had nothing to do with him.

ABC's Jessica Hopper contributed to this report.