Israel destroyed a top secret nuclear weapons research facility during its missile attack on Iran last month, it was reported Friday.
The Taleghan 2 facility in the Parchin military complex, located roughly 20 miles southeast of Tehran, previously had been reported to be inactive.
Instead, Israel's missiles significantly damaged Iran's effort during the past year to resume nuclear weapons research, multiple officials told Axios.
Officials told the outlet that the Taleghan 2 facility was used to conduct nuclear weapons research that also could be presented as research for civilian purposes.
"They conducted scientific activity that could lay the ground for the production of a nuclear weapon. It was a top secret thing. A small part of the Iranian government knew about this, but most of the Iranian government didn't," one U.S. official told Axios.
The attack destroyed sophisticated equipment used to design the plastic explosives that surround uranium in nuclear devices and are needed to detonate them, an ex-Israeli official told the outlet.
After Israeli and U.S. intelligence detected research activity at Parchin earlier this year, White House officials warned the Iranians to stop the undertaking.
On Oct. 25, Israel delivered its long-expected response to Iranian missile attacks by carrying out a series of airstrikes against the Islamic Republic.
The strikes did not appear to target facilities that would all but ensure a harsh Iranian response. Those most notably include Iran's oil infrastructure, the backbone of the OPEC member's economy, and its nuclear facilities.
President Joe Biden earlier last month said he would not support an Israeli strike on Iranian nuclear sites.
Because Taleghan 2 was not part of Iran's declared nuclear program, Iran wouldn't be able to acknowledge the importance of the attack without admitting they violated the nuclear non-proliferation treaty.
Iran has denied it is pursuing nuclear weapons.
The Institute for Science and International Security reported that the Taleghan 2 facility, as part of the Iranian Amad nuclear weapons program, was used for testing explosives needed to set off a nuclear device before Iran supposedly halted its military nuclear program in 2003.
After Israeli strikes last month, the institute acquired high-resolution satellite imagery showing the Taleghan 2 building was completely destroyed.