A White House supply clerk was arrested late last week after he allegedly used an illegal handgun to detain a man he suspected of having tampered with the clerk's automobile parked near the White House, the Secret Service said yesterday.

Ramon S. Pineda, 28, was arrested by U.S. Park Police Thursday evening after a call for assistance from a uniformed Secret Service officer who had spotted Pineda holding another man, Herman Levi Herrimaen, 29, at gunpoint, according to Secret Service special agent William Corbett.

Pineda, a clerk in the White House Office of Administration and Supply in the Old Executive Office Building, told police he "ran up to the guy, pushed him aside, jumped into the car, jumped out with a gun and held Herrimaen at bay" for one or two minutes, Corbett said.

Pineda, who lives in Maryland, has been charged with carrying an illegal weapon and ammunition in violation of District law, Corbett said. He said Herrimaen, a transient, was charged with tampering with an automobile.

Park Police officials said Herrimaen was held overnight and Pineda was released Thursday night. They would not say if or when either man would be arraigned or fined.

The incident came up yesterday during a White House briefing. "I'd have given the guy Pineda a medal," White House spokesman Larry Speakes told reporters, according to United Press International.

Staff members are not required to pass through metal detection devices, but Corbett said it is fairly certain that Pineda, who was issued a security pass in July 1984, did not take the gun into the Executive Office Building or the White House.