(Corrects spelling of name to Jafarzadeh from Jafarazadeh throughout) WASHINGTON, Jan 5 (Reuters) - Iran has sharply increased its efforts to fan sectarian violence in Iraq in recent months, easily transferring money and arms across the Iraqi border, an opponent of the Tehran government said on Friday. Alireza Jafarzadeh, who accurately disclosed key details about Iran's nuclear program in 2002, gave names, locations and logistics he said were associated with Iranian operations in neighboring Iraq, which includes providing roadside bombs that have killed U.S. forces. Jafarzadeh spoke at a news conference organized by the Iran Policy Committee, a U.S. group pushing for regime change in Iran. He said his information came from Iran-based members of the People's Mujahideen, which seeks to topple Iran's fundamentalist government and is on the U.S. list of extremist organizations. Iran denies that it is fueling sectarian violence or the anti-U.S. insurgency in Iraq. However, retired U.S. Air Force General Thomas McInerney, a policy committee member said Jafarzadeh's presentation was "powerful evidence" that Iran has become the primary killer of U.S. forces in Iraq. He said it should force President George W. Bush, who is preparing to announce changes in his Iraq policy, to confront Iran's role directly if he wants to stabilize Iraq. "Just sending more troops to Iraq doesn't solve the problem unless you attack this problem (of Iran's involvement) and it must be attacked in a covert way in Iran. We're going against a very formidable enemy that thinks we will not respond," McInerney said. Since 2003, Iran has spent billions of dollars in Iraq, mobilized vast government resources and unleashed the Qods force of the Islamic revolutionary Guard "to impose its authority in Iraq," Jafarzadeh said. But in the past few months, there has been a "sharp increase in Iran's sponsorship of terrorism and sectarian violence," he said. McInerney said the most sophisticated roadside bombs killing U.S. troops and Iraqi civilians in Iraq are from Iran and Jafarzadeh said a major front organization used by the Qods force to deliver arms and ammunition into Iraq is called the "headquarters for reconstruction of Iraq's holy sites." The reconstruction organization "has reached agreements with local authorities in different Iraqi provinces so that containers of goods arriving from Iran are not inspected at the border and are delivered sealed to Najaf, Karbala and Baghdad," he said. "The Qods force hides arms and ammunitions in these containers," he said.