Three FBI (search) agents arrived in northern Brazil to investigate the killing of American nun Dorothy Stang, Brazilian media said Saturday.

The agents arrived Friday in Altamira, about 80 miles from the rural town where the 73-year-old Stang was killed on Feb. 12, said the Folha de S. Paulo (search) newspaper, Brazil's largest.

The agents met with local police officers and interrogated the two suspected gunmen charged with the killing, Folha and other local media said. They were expected to report to the U.S. State Department (search) after finishing their investigation.

On Saturday, the agents visited the location where Stang was shot, a settlement near the town of Anapu on the Trans-Amazon highway, about 1,250 miles north of Rio de Janeiro.

The agents said they would not interfere with local police. "We are impressed with how the local investigation has been conducted," agent Richard Cavalieros told Folha.

It was not immediately clear how long the agents would stay in the area.

The FBI's presence had been requested shortly after the killing by the Congregation of the Sisters of Notre Dame de Namur, an international Roman Catholic religious order of which Stang was a member.

The naturalized Brazilian originally from near Dayton, Ohio, spent the last 23 years of her life in Brazil's lawless Para state, trying to protect the rain forest and peasants from loggers and ranchers vying for the area's rich natural resources.

She was killed by gunmen allegedly hired by the rancher Vitalmiro Moura, who wanted to log the area she was trying to protect and whose ownership was being disputed in the courts.

On Friday, the government awarded a disputed patch of Amazon rain forest to a sustainable development project championed by the slain American nun.

Sustainable development projects are a zoning mechanism under which the government grants plots of land to poor settlers under the agreement that they farm in ways that leave most of the forest intact.

Environmentalists say the Amazon loses 9,170 square miles of forest every year, and that about 20 percent of the 1.6 million square miles of wilderness has already been cut down.