James O’Keefe declined to answer questions on Nov. 27 about a woman working with Project Veritas who falsely claimed to Washington Post reporters that Senate candidate Roy Moore impregnated her when she was a teenager. (Dalton Bennett/The Washington Post)

Project Veritas, an activist group that mounts undercover video stings of liberals and mainstream news organizations, received nearly $1.7 million in donations last year from a giant charity associated with the Koch brothers, according to documents filed with the Internal Revenue Service.

The donations pushed Project Veritas contributions to new highs during the 2016 presidential election and highlight the prominent spot the group occupies in a national network of conservative nonprofits that strongly supported Donald Trump over Democrat Hillary Clinton.

Project Veritas, a tax-exempt public charity, purports to expose what it calls dishonesty and corruption. An operative working with the group in recent weeks falsely claimed to two Washington Post reporters that U.S. Senate candidate Roy Moore impregnated her as a teenager. The Post did not publish a story based on her account, which collapsed under reporters’ scrutiny.

[A woman approached The Post with dramatic — and false — tale about Roy Moore. She appears to be part of undercover sting operation.]

The $1.7 million came through Donors Trust, a type of tax-exempt charity called a donor-advised fund (DAF). Billionaire industrialists Charles and David Koch and other wealthy conservatives rely on Donors Trust and similar groups to finance numerous charities and other nonprofit organizations to promote libertarian, small-government and free-market policies and candidates, according to Robert Brulle, a professor of sociology and environmental science at Drexel University, who tracks such spending.

For example, Charles Koch has long served as chairman or director of the Knowledge and Progress Fund Inc., a tax-exempt private foundation that donated millions to Donors Trust since the mid-2000s, IRS filings show. In 2015, the most recent year for available IRS filings, Knowledge and Progress gave Donors Trust $5.2 million — its only contribution for the year.

Donors’ identities are not disclosed, even in filings to the government.

“Unlike other donor-advised plans, DonorsTrust is absolutely committed to a clearly defined purpose and mission–supporting causes and public policies that preserve our constitutionally protected liberties and strengthen American civil society through private institutions rather than government programs,” the Donors’ website says.

Wealthy donors made at least 15 tax-deductible contributions to Project Veritas through Donors Trust in 2016, gifts that amounted to more than a third of the $4.9 million Project Veritas received that year, IRS filings show.

The smallest contribution was $600, the largest $550,000. Project Veritas founder and chairman James O’Keefe received more than $320,000 in pay last year, documents show.

Project Veritas received about $1.5 million through Donors Trust in 2015, documents show. Like other charities, Project Veritas does not disclose the identities of its own donors.

Donors Trust officials provided The Post with their annual IRS filings, known as 990 forms. In a written statement, the group stressed that it was under no legal obligation to name donors. “As an aside, we would like to draw your attention to the fact that over the 2011-2016 period, Project Veritas received less than 0.75 percent (or 3/4 of 1 percent) of the over $500 million of DonorsTrust grants issued upon the advice of its DAF account holders,” the statement said.

Project Veritas’s popularity among conservative donors has been on the ascent since it was formed in 2010 by O’Keefe, who first earned notoriety for a video sting of ACORN, a social services organization.

Since then, the group has staged many undercover operations, with an increasing focus on mainstream news organizations. The failed effort to plant a false story about Moore in The Post was part of a months-long campaign to infiltrate The Post and other media outlets in Washington and New York.

[Woman’s effort to infiltrate The Washington Post dated back months]

After Trump’s election last year, O’Keefe was applauded by wealthy contributors at a conservative retreat when he announced that his group and other conservatives had discredited mainstream media.

“It’s dead and we have killed it and it’s been a long time coming,” he told the audience.

Project Veritas is among a wide array of conservative groups that have received financial support from Donors Trust. Others include the Competitive Enterprise Institute, the State Policy Network, the Franklin Center and the Government Accountability Institute, a public charity started by former Trump adviser Stephen K. Bannon that worked closely with Breitbart News in the run-up to the presidential election.

A Project Veritas spokesman declined to answer questions about the donations and referred questions to Donors Trust.

Other contributors to Project Veritas in recent years include Donors Capital Fund, another group in the Koch brothers’ network, and Gravitas Maximus LLC, an organization controlled by the Mercer family, according to IRS filings by Project Veritas that inadvertently disclosed some donors identities first discovered by Eli Clifton, a fellow at the Nation Institute. Under Bannon’s guidance, the Mercer family in recent years became one of the most prominent funders of right-wing causes.

Individuals such as Robert Shillman, a large contributor to the conservative David Horowitz Freedom Center, also donated, IRS filings show.