Peshawar, Pakistan – Security officials in Pakistan are still questioning an American claiming to be a bounty hunter on the trail of the world’s most wanted man — Osama bin Laden.

Three teams of civilian and military intelligence officials have been questioning Gary Faulkner, in Peshawar city.

An intelligence official in Chitral, who asked not to be identified, said Faulkner shouted “don’t come closer to me or I’ll open fire!” when approached while being detained.

Pakistani investigators plan to conduct psychological tests on Faulkner, an investigator said Wednesday.

Pakistan conducted psychological tests Wednesday on an American construction worker arrested on suspicion of wanting to hunt down and kill Usama bin Laden.

Gary Brooks Faulkner was detained Monday in the remote mountains of Chitral, once a rumored hiding place of bin Laden, near Afghanistan’s Nuristan province, armed with a pistol, dagger, sword and night-vision equipment.

He was taken to Pakistan’s northwestern city of Peshawar, to be interrogated by intelligence agents and investigators, officials said.

“They are asking him a lot of things, especially about the sword and dagger that look like ceremonial weapons. He said he wanted to kill Usama but killing Usama with a sword and dagger is not child’s play,” one investigator told AFP.

“Carrying a pistol and such a long sword is definitely a crime but we need a lot more clarifications.

Police officer Mumtaz Ahmad Khan said the 50-year-old long-haired and bearded American from Colorado, who suffers from kidney problems and high blood pressure, was sane but “frustrated.”

“A doctor examined the American and spent about 30 minutes with him,” an intelligence official in Peshawar later confirmed to AFP.

“The doctor told us he has some psychological problems but said he is not a mad man,” the official added.

Earlier, Faulkner’s brother said the would-be hitman — whom the U.S. press quickly dubbed “the American Ninja” — was “not crazy”.

Scott Faulkner said his sibling was motivated by patriotism and a belief in God rather than the prospect of the $25 million bounty for bin Laden, the world’s most wanted man.

After the Sept. 11 attacks, Scott Faulkner said his brother began visiting Pakistan to try to find bin Laden because he felt the U.S. military was not “doing enough,” The Wall Street Journal reported.

“Who says, ‘Why do I rob banks? Because that’s where the money is,'” Scott Faulkner asked, saying the brothers went to Pakistan because “that’s where Usama is.”

Scott Faulkner said his brother carried no weapons when he flew out of Denver, but “he took wire ties (for use) as handcuffs. If he could take (bin Laden) alive, he would,” Scott Faulkner told Fox News Channel.

Hugo Corral, a barber in Greeley, Colo., told the New York Post he cut Gary’ Faulkner’s hair in March and days afterward saw “him marching down the street with army pants on and cussing. He would stop and salute.”

“He was a pretty weird guy,” Corral said.

Police in Pakistan said Faulkner arrived as a tourist in Chitral on June 3, checked into a hotel, was given the customary security escort, then vanished.

The U.S. embassy in Islamabad said American consular officials were working with the Pakistani authorities to gain consular access to the man.