Iran and Israel’s shadowy intelligence war has escalated with a group of Iranian dissidents claiming to leak a new nuclear weapons program by the Islamic Republic after Tehran shortly after Tehran alleged to have seized information alleged to be related to Israel’s nuclear program.

The latest salvo came Tuesday as the National Council of Resistance of Iran (NCRI) unveiled what it alleged to be steps taken by the Iranian government to produce nuclear weapons at a press conference in Washington, D.C. The information was said to have been obtained by the NCRI’s leading faction, the Mojahedin-e-Khelq (MeK), also known as the People’s Mojahedin Organization of Iran (PMOI).

The so-called “Kavir Plan,” according to MeK spokesperson Alireza Jafarzadeh, involved at least six sites in the desert of Iran’s Semnan province dedicated to advancing nuclear weapons technology, including the development of warheads and detonators as well as conducting tests. The plan was said to replace the previous “Amad Plan” that reportedly ran from 1999 to 2003, when Jafarzadeh said the MeK’s revelations forced the Iranian government to shutter the program.

“The Kavir Plan is not just a replacement for the Amad Plan, but it’s a more advanced, a more sophisticated and more secure plan than the original one,” Jafarzadeh told Newsweek.

Iranian officials have always denied pursuing nuclear weapons and have long dismissed alleged leaks by the MeK, which Tehran considers to be a terrorist organization.

The MeK’s efforts to in expose Iranian nuclear secrets dates back to at least 2002, when the group revealed the existence of the Natanz uranium enrichment site and Arak heavy water plant. The campaign has run in parallel with efforts by Israel to target and unveil covert Iranian nuclear activity, including a 2018 raid by the Mossad intelligence agency through which Prime Minister Benjamin Netanyahu claimed to have obtained up to 100,000 documents related to Iran’s nuclear program.

Jafarzadeh declined to comment on whether or not the MeK was cooperating with Israel on the issue. However, he confirmed that the information was being shared with President Donald Trump’s administration as well as the International Atomic Energy Agency (IAEA).

“Here in the United States, we only deal with the U.S. government, U.S. Congress and public,” Jafarzadeh said. “So, the U.S. government does have this information. The IAEA also has the information.”

Newsweek has reached out to the Iranian Mission to the United Nations and the Israeli Consulate General in New York.