Washington (CNN) -- Supporters of an Iranian opposition group claimed Thursday they have information about another secret facility tied to the Iranian government's nuclear program.
According to Alireza Jafarzadeh, an Iranian-American with ties to the People's Mujahedeen of Iran, the facility is at a site referred to as TABA, just west of Tehran, and is designed to manufacture parts for centrifuges used to enrich uranium, a key component for civilian nuclear power as well as for nuclear weapons.
A U.S. official who is not authorized to speak on the record said the United States is aware of the facility.
Jafarzadeh told reporters at a news conference that over the past four and a half years the plant has produced enough parts to make more than 100,000 centrifuges, well beyond the needs for the nuclear facilities declared by the Iranian government to international monitors. He also maintained the site is under the control and supervision of the Iranian Defense Ministry.
The International Atomic Energy Agency, which monitors nuclear activities on behalf of the United Nations, has inspected Iran's declared enrichment facilities, but Iran does not provide details or access to sites where nuclear components are made.
Soona Samsami, another supporter of the People's Mujahedeen of Iran, said the TABA site comprises three main warehouses over an area of nearly 48,000 square meters, or nearly 12 acres. She said the essential parts manufactured there include casings, magnets, molecular pumps, composite tubes, bellows and centrifuge bases.
Although satellite photos were shown of the site, no direct evidence was provided other than to say the information was from members of the People's Mujahedeen organization inside Iran. The same group was the first to provide the details that publicly exposed the existence of Iran's clandestine nuclear program in 2002.
Iran claims its nuclear program is for civilian energy needs, but the United States and other nations maintain Iran is working to develop fissile material for nuclear weapons.
The International Atomic Energy Agency said in its most recent report, in February, that Iran continues to stonewall the inspectors by not providing sufficient information or access to its facilities for inspectors to determine the ultimate purpose of Iran's nuclear program.
Former nuclear inspector David Albright, who has closely followed developments concerning Iran's nuclear exploits, said he had no information about whether TABA is in fact a secret nuclear site. But he did question the claim that Iran has enough parts to make 100,000 centrifuges.
"There is no way Iran has made components for 100,000 centrifuges," said Albright, adding, "It runs contrary to all indications that Iran has a shortage of raw materials."
According to Albright, Iran has indicated it wants to have 50,000 centrifuges and has so far manufactured 12,000 to 15,000 of them.
Albright believes there is a political motivation behind the Iranian opposition's claims that leads to exaggeration. He said the opposition supporters challenge international sanctions as a way to highlight their goal of getting the United States to remove the People's Mujahedeen of Iran from its list of foreign terrorist organizations.
At the news conference, Jafarzadeh -- saying that "the revelations today show the policy pursued by the United States has not been productive in halting the nuclear program of Iran" -- maintained that only a democratic Iran will succeed in eliminating the nuclear program, and that the best chance for democracy lies with the United States removing the People's Mujahedeen of Iran from its terrorist list.