An aide to Mayor Richard Riordan used his city e-mail to gather a computer list of city employees whom he then solicited for support for a school board candidate backed by the mayor.
A spokeswoman for Riordan apologized Monday for the action of Assistant Deputy Mayor John Lee, which appears to have violated city policy prohibiting use of city e-mail for personal or political purposes.
"There appears to have been an unfortunate mistake," said spokeswoman Noelia Rodriguez, adding it was "an error of judgment that we expect won't happen again."
Rodriguez said the mayor was not aware of Lee's actions.
The incident involves Lee's work as paid campaign manager for former mayoral aide Caprice Young, a candidate for the Los Angeles Unified School District Board.
Lee, who will be on a leave through the April elections, would not comment on the matter but said through a spokesman that he did not intend to violate city policy.
"Any error that was made was unintentional and will not happen again," said Jason Greenwald, a spokesman for Lee.
Lee appears to have violated the city's e-mail policy, said James Crain, assistant general manager of the city Information Technology Agency.
"It [e-mail use] clearly appears campaign-related and appears inappropriate," Crain said.
Young is part of a slate of Los Angeles school board candidates being pushed by Riordan. She is running against incumbent Jeff Horton.
In an e-mail message sent Saturday by Lee from his home, using his private e-mail address, Lee asked about 18 city employees to help him gather signatures to qualify Young as a candidate in the Third District race.
"I need volunteers to donate two hours to get qualifying signatures for the petition to get on the April ballot," Lee wrote.
A message Lee sent from home Saturday soliciting support included an attachment indicating that Lee had used his e-mail address in the mayor's office to gather the list.
The city Ethics Commission is investigating.
"It's a use of taxpayer funds for political purposes," said Councilwoman Jackie Goldberg. "It's an outrage."
Horton also criticized the use of the mayor's e-mail system to boost the campaign against him.
"If the city communications network is funded by tax dollars, I think that's not right," Horton said.