To prepare for a legal battle between a fired City Council aide, Viola Plummer, and Speaker Christine Quinn, City Hall computer technicians are being dispatched to the district offices of some council members to search for documents related to the lawsuit, a City Hall source said.

Ms. Quinn fired Plummer after the aide promised to end the political career of a council member of Queens, Leroy Comrie, even if it took “an assassination.”

Plummer, the former chief of staff to Council Member Charles Barron of Brooklyn, sued the speaker in federal court for $1 million over the dismissal. The case is scheduled to go to trial on September 24.

A senior advisor to Majority Leader Joel Rivera, Michael Nieves, said people from the council’s computer services division came to the council member’s district office on Wednesday, but he doesn’t know what was done during the visit.

“They showed up. I don’t know why or when,” he said, adding that he didn’t question them. “I’m assuming they are going to do whatever they have to do.”

A City Hall source said at least one other council member’s office in the Bronx has been visited. Privately, at least one council member balked at the searches, calling them “insane,” in part because the council’s computer system is equipped to allow all documents to be accessed from City Hall.

A spokeswoman for Ms. Quinn, Maria Alvarado, would not answer questions about the office searches, saying she is not commenting on any case that is in litigation.

The unusual house calls come on the heels of an e-mail message to all council members from the office of the City Council’s general counsel in early July asking members to save all information related to Plummer and a proposal she supported to rename a street after a black activist, Sonny Carson. The e-mail asks specifically that members save e-mail messages, documents on their computers, and voicemails related to the aide and the street renaming.

“You may find it helpful to set up a folder on your email system(s), and a physical folder for your hardcopy documents,” the letter says.

The target of Plummer’s threat, Mr. Comrie, who abstained from supporting the proposal to rename a Brooklyn street after Carson, said he was not aware of any computer technicians searching his office, but added that he wouldn’t have a problem if they dropped by.

“I didn’t do any e-mails on that issue that I’m aware of,” he said.