DENVER — A government official suggested yesterday that three people who arrived at President Bush's town hall meeting here last week were removed by a Republican operative they mistook for a Secret Service agent.

"It was somebody from the host committee," Secret Service spokesman Tom Mazur said. A spokeswoman for the Colorado Republican Party said her organization was not involved. White House spokesman Allen Abney said it was a volunteer, not a paid White House staffer, who removed the three people.

The man's name was not released.

Dan Recht, an attorney for the three self-described progressives who were removed, said he was getting "the run-around" about the matter and sent a letter yesterday asking Attorney General Alberto Gonzales to launch an investigation.

Recht's letter said the man who removed his clients may have illegally impersonated a Secret Service agent, used illegal physical force to remove his clients, and violated his clients' First Amendment rights. He also sought investigation of the use of taxpayer funds for events at which certain citizens are excluded.

"If this person was acting within the scope of his employment and was instructed to remove people for these kind of things, then that staff person and the Republican Party violated my clients' First Amendment rights, and I would be inclined to sue them for violation of constitutional rights," Recht said.

Internet technology worker Alex Young, 25; marketing coordinator Karen Bauer, 38; and lawyer Leslie Weise, 39, arrived at the March 21 meeting at the Wings Over the Rockies Museum in a car with a bumper sticker reading "No More Blood for Oil" and said someone wearing an earpiece, navy blue suit and lapel pin asked them to leave. They assumed he was a Secret Service agent.

The three were overheard in line talking about how they planned to disrupt the event with protest, Courtney Walsh, sales director at the museum told The Denver Post. It was unclear if Walsh saw the three while they were waiting in line.

"They got exactly what they deserved," she said.

Abney said the volunteer probably believed the three were attending the event to disrupt it.

"We welcome a diversity of views, but if people come to disrupt the event, that's another matter. There's plenty of opportunity to express views outside the event."

Recht agreed but said his clients had done nothing wrong before they were removed.

Bauer said the man would not say his name, who he was, where he was from, and why they were being removed.

Recht said Denver Secret Service agent-in-charge Lon Garner told him the person who escorted his clients out was a Republican staffer but did not give a name. Recht did not know whether the man was affiliated with the local or national party or who trained him.

Garner referred all calls to Mazur, who is based in Washington, D.C.

"We're simply asking for answers," Recht said. "We're asking the attorney general for answers to questions that would help us decide if we ought to bring a lawsuit, and if so, against whom."

Abney said taxpayer funds were used and that the event was ticketed, with the public getting tickets from various organizations or Colorado Republican Rep. Bob Beauprez's office.