A State Department official deleted emails that included information about a secret campaign to oust Prime Minister Benjamin Netanyahu during the country’s last election, according to a Senate investigatory committee that determined the Obama administration transferred tax funds to anti-Netanyahu groups.

The Senate Permanent Subcommittee on Investigations disclosed in a massive report on Tuesday that the Obama administration provided U.S. taxpayer dollars to the OneVoice Movement, a liberal group that waged a clandestine campaign to smear and oust Netanyahu from office.

OneVoice, which was awarded $465,000 in U.S. grants through 2014, has been under congressional investigation since 2015, when it was first accused of funneling money to partisan political groups looking to unseat Netanyahu. This type of behavior by non-profit groups is prohibited under U.S. tax law.

The investigation determined that OneVoice redirected State Department funds to anti-Netanyahu efforts and that U.S. officials subsequently erased emails containing information about the administration’s relationship with the non-profit group.

The disclosure comes amid a massive effort by Congress to reform the State Department’s email practices in light of former Secretary of State and Democratic presidential frontrunner’s Hillary Clinton’s mishandling of classified materials.

The Washington Free Beacon revealed early Tuesday that new legislation would ban all State Department officials from using private email accounts and servers, as well as mandate annual reports about the leak of classified information.

A senior State Department official admitted to congressional investigators that he deleted several emails pertaining to the administration’s coordination with OneVoice.

“The State Department was unable to produce all documents responsive to the Subcommittee’s requests due to its failure to retain complete email records of Michael Ratney, who served as U.S. Consul General in Jerusalem during the award and oversight of the OneVoice grants,” the report states.

Investigators “discovered this retention problem because one important email exchange between OneVoice and Mr. Ratney … was produced to the Subcommittee only by OneVoice,” the report continues. “After conducting additional searches, the Department informed the Subcommittee that it was unable to locate any responsive emails from Mr. Ratney’s inbox or sent mail.”

Ratney was ultimately forced to tell investigators that “[a]t times I deleted emails with attachments I didn’t need in order to maintain my inbox under the storage limit.”