Families of American victims of the Hamas-led terrorist attack on Oct. 7 and those killed fighting in Gaza sued Iran on Sunday, accusing it of supporting the single deadliest massacre of Jews since the Holocaust.

The lawsuit, filed in U.S. District Court in Washington, details Iran’s funding of Hamas and its embrace of other terrorist organizations seeking to destroy Israel. The lawsuit relies, at least partly, on Hamas documents that were seized in Gaza and published in the news media, including The New York Times.

But lawyers for the plaintiffs in the case also appear to have obtained original documents that refer to a secret planning meeting of a small group of Hamas’s political and military leaders in December 2022.

During the meeting, Yahya Sinwar, then the leader of the group in Gaza, requested an additional $7 million a month from the Islamic Revolutionary Guard Corps to fund the attack on Oct. 7, known as the “big project.”

The Times has independently reviewed a set of the documents that refer to the $7 million, including details about the way Hamas’s leadership works and the preparations that went into its attack.

The lawsuit also mentions the role of the Revolutionary Guards in coordinating between Hamas and Hezbollah, a regional ally, in preparation for the attack, which The Times has reported.