A federal grand jury in San Francisco is scheduled to begin questioning Peoples Temple members today in an effort to determine if there was a conspiracy to murder Rep. Leo J. Ryan (D-Calif.).

Among those subpoenaed to testify are 17 Temple members who recently returned from Guyana, where the Ryan ambush and cult mass suicides occurred on Nov. 18.

The FBI has already interviewed hundreds of Temple members and associates concerning the Ryan murder, and the Justice Department is conducting a parallel investigation into the financial affairs of the organization.

There were reports that lawyers Charles Garry and Mark Lane, who were in Jonestown at the time, might be among those to be questioned, but Lane said last night in a telephone interview that he had neither been subpoenaed nor asked to testify.

Lane met with federal authorities in the San Francisco area Wednesday and discussed "the question of immunity... for my client," Terry Buford, who had been one of the Temple's key operatives. He said U.S. Attorney William Hunter told him at the end of the meeting that he saw no need for it.

Waxing indignant, Lane also hotly denied broaching the subject of immunity for himself, as had been reported in the Los Angeles Times.

The Guyanese government has filed murder charges against one Temple member, Larry Layton. The U.S. government is basing its investigation on a statute making it a federal crime to conspire to kill a member of Congress.