WASHINGTON – US military officials on Monday adamantly rejected allegations in a magazine article that the army used psychological operations to influence American lawmakers on the Afghanistan war.

Commanders in charge of training Afghan troops had asked staff members for routine research using publicly available information about the views of visiting lawmakers and did not order deceptive methods usually employed against enemy armies, military officials said.

A military lawyer had looked into the case and concluded the orders were lawful, the officials said.

The allegations in last week's Rolling Stone magazine article come from an army lieutenant colonel, Michael Holmes, who charges he was asked to violate regulations and use his "information operations" techniques on prominent senators.

The article has prompted an official investigation, ordered by the commander of US and NATO troops in Afghanistan, General David Petraeus, but officials in Kabul and Washington have pushed back against the allegations.

When Lieutenant General William Caldwell took over the NATO training mission in Afghanistan, he ordered an end to information operations which he deemed unnecessary for a unit overseeing training Afghan soldiers and police, said a military official, who spoke on condition of anonymity.

When Holmes was asked to carry out standard communications work instead of his information operations specialty, he objected, saying it violated rules meant to separate public relations from deception aimed at adversaries, the official said.

The head of communications for the training mission, Lieutenant Colonel Shawn Stroud, said Holmes or others with information operations were asked to help with routine work and not ordered to engage in psychological manipulation against VIP visitors.

"I categorically deny the assertion that NTM-A used an Information Operations cell to influence distinguished visitors," Stroud said in a "personal" statement released to AFP on Monday.

"Personnel with backgrounds in IO (information operations) were utilized only because of their availability. They were never directed to use their specific IO skills while preparing background information for the command in advance of distinguished guest visits," he said.

He also said a staff military lawyer determined that having Holmes participate in the effort was "completely legal."

Stroud called the Rolling Stone article inaccurate and based solely on one source.

Another piece last year in Rolling Stone, written by the same reporter, Michael Hastings, led to the sacking of Petraeus' predecessor, General Stanley McChrystal.

The profile, titled "The Runaway General," quoted McChrystal's staff castigating civilian leaders in the White House, including President Barack Obama.