Sadegh Ghotbzadeh, Iran's former foreign minister, has been arrested, close family acquaintances said today.

It was not immediately clear why or where he was being held. Sketchy and often contradictory reports suggested that Revolutionary Guards arrested Ghotbzadeh sometime during the past two days at his house in north Tehran.

A spokesman for Tehran's Central Committee, the chief security organization, denied that Ghotbzadeh had been arrested, United Press International reported.

Ghotbzadeh's acquaintances said his brother and several friends were also arrested.

Since ending his government functions in the summer of 1980, Ghotbzadeh has maintained a low profile and avoided any overt political activity. He was briefly arrested in the fall of 1980 and detained at Tehran's Evin Prison, but national leader Ayatollah Ruhollah Khomeini's son Ahmed personally intervened and arranged his release.

Ghotbzadeh incurred the enmity of more radical wings of the ruling clerical Islamic Republican Party while serving as foreign minister in 1979 and 1980 during most of the long incarceration of the American hostages at the U.S. Embassy. His efforts to resolve the crisis were considered in most fundamentalist quarters as betraying a pro-American tilt and he has been under a political cloud ever since.