A recently created Republican super PAC behind a slate of inflammatory ads targeting Vice President Kamala Harris’ Israel record has been exclusively funded by a political advocacy group called Building America’s Future, according to federal campaign finance filings released on Tuesday.

The GOP-aligned group contributed $3 million to Future Coalition PAC, which has been running digital ads in Michigan and Pennsylvania alternately portraying Harris as hostile and friendly to Israel — in an effort to target Muslim and Jewish voters who could be decisive in a close election.

Future Coalition PAC, whose funding had been a source of mystery, has been criticized by members of both parties for engaging in a cynically motivated strategy to play both sides of a polarizing issue.

In addition, some of its ads have faced scrutiny for relying on antisemitic tropes about Second Gentleman Doug Emhoff, Harris’ Jewish husband.

The super PAC, launched in July, has spent nearly $2.5 million in the election on ads supporting and opposing Harris and Rep. Elissa Slotkin (D-MI), a Jewish Democrat running for Senate in Michigan.

The contributions from Building America’s Future were first reported by The New York Times on Tuesday.

Building America’s Future, a political nonprofit, is not required to disclose its donors, but one notable financial supporter has been Elon Musk, according to a recent Wall Street Journal report.

The group, which has donated to other super PACs this cycle, has been led by four GOP consultants and operatives previously involved in Florida Gov. Ron DeSantis’ failed presidential campaign, according to the New York Times.

Future Coalition PAC did not return a request for comment.