Because Iran and the United States do not have diplomatic relations, the protest was made to the Swiss ambassador in Tehran, The New York Times reported.
The Fars News Agency Iran described the drone as being "equipped with highly advanced surveillance, data gathering, electronic communication and radar systems."
In the clip shown on television, the drone appeared intact, suffering little damage, the Times said. A Revolutionary Guard commander said it "was detected by Iranian radar as soon as it entered Iranian airspace and was brought down by Iran's military systems with the minimum damage possible."
The CIA drone was part of a surveillance program to map suspected nuclear sites, foreign and U.S. experts said.
The high-altitude flights from Afghanistan were among the most guarded of intelligence-collection efforts against Iran, but the crash, which Iranian officials said happened more than 140 miles from the Afghan border, changed things, the Times said..
The RQ-170 was used to model Osama bin Laden's compound in Pakistan before the U.S. raid in May. The drone's missions in Iran included looking for tunnels, underground facilities or other places where centrifuge parts or enrichment facilities could be built, officials said.
Experts raised questions about whether Iran could reverse-engineer the drone's technology. They said Tehran also could sell the drone to China, Russia or other interested countries.
P.W. Singer, who studies military robotics at the Brookings Institution, told the Times the most prized technology on the craft likely was its sensors, which may include a sophisticated radar system.
Besides the sensors, the unmanned aircraft likely contained video cameras and communications intercept equipment, the experts said.
Dennis Gormley, a missile and drone expert at the University of Pittsburgh, said reverse engineering would be difficult.
"Unless somebody put the engineering drawings in the [unmanned aircraft], it won't be easy," he said. "In any complex piece of aviation equipment, you have to replicate the tolerances precisely."