A Super PAC closely aligned with Senate Majority Leader Mitch McConnell is launching a new digital ad targeting Republican Senate candidate Danny Tarkanian over a series of loans and money transfers between his charity, a business and his 2012 congressional campaign.

The ad, entitled 'Whiteboard,' is the Senate Leadership Fund's latest foray into the Nevada Senate primary after it had pledged in August to spend seven figures defending Sen. Dean Heller, widely considered one of the Senate's most vulnerable incumbents. The group spent $14 million in Nevada's 2016 U.S. Senate race.

The 85-second ad primarily consists of a slightly edited Channel 8 news segment by political reporter Steve Sebelius, detailing a complex financial transaction during which Tarkanian loaned $40,000 from his charity, the Tarkanian Basketball Academy, to a personal business, then to his personal account, and then to his campaign account. Tarkanian transferred the money back to himself several days later, and used it as part of a $300,000 mortgage payment to avoid a foreclosure on his home.

Tarkanian has strongly pushed back on the story, saying the story was "grasping at straws" and that the loan made by the charity was paid back with interest.

The ad is set to run on social media, search ads and on websites.