SEATTLE (AP) - What began months ago as an inquiry into maintenance practices at an Alaska Airlines facility has become a criminal investigation into the deadly crash of Flight 261, The Seattle Times reported Saturday.
Citing unidentified sources, the newspaper said the FBI and Department of Transportation investigators have been questioning Alaska Airlines employees as part of an inquiry that has been under way for several weeks.
No criminal wrongdoing has been established in connection with the Jan. 31 crash off the coast of California that killed 88 people, the Times said.
The criminal investigation grew out of a 15-month-old inquiry into practices at Alaska's maintenance facility at Oakland, Calif., the Times said. In that inquiry, a grand jury in San Francisco is investigating whether supervisors signed for repairs that weren't done or that they weren't authorized to approve.
The Times said the FBI, which usually plays an advisory role to the NTSB, is conducting a separate, parallel investigation - a course of action reserved for cases where there is evidence or suspicion of crime.
The newspaper cited three sources in two federal agencies as confirming the investigation.
FBI spokeswomen Roberta Burroughs in Seattle and Debbie Weierman in Washington, D.C., on Saturday would not confirm or deny the existence of any such investigation.
Alaska Airlines said it was not aware of a criminal probe.
''The FBI has been involved in the investigation of Flight 261 since the beginning,'' airlines spokesman Jack Evans said Saturday. ''Currently, we are unaware of any change in their role since the beginning. If there is a change in that role, we'll cooperate with them as we have been.''
Earlier in the week, the airline said it put a top manager on leave while it investigates claims by 64 Seattle mechanics that they were ''pressured, threatened and intimidated'' to cut corners on repairs.
Alaska Airlines said it had notified federal prosecutors and the National Transportation Safety Board of the claims. It also said it would immediately ground any planes found to be potentially unsafe. No such action had been deemed necessary as of Saturday, Evans said.
The mechanics' complaints were contained in a letter delivered to the airline on Thursday. The airline and the Federal Aviation Administration have begun interviewing the mechanics.
''We increased our oversight as soon as we found out about the letter,'' FAA spokeswoman Rebecca Trexler said Saturday.
NTSB Chairman Jim Hall said Friday that most major components of Flight 261's tail section have been recovered. He also said investigators had found no grease on a crucial portion of the jackscrew that helped control the movement of the jet's horizontal tail stabilizer, long a focus of the crash probe.
The Times reported that the mechanics' letter was triggered by concerns over a recent repair to the horizontal stabilizer and jackscrew assembly on an MD-80 jetliner. An airline spokesman could not confirm that report Saturday.
FAA spokesman Mitch Barker said the agency was aware there had been recent ''debate'' at Alaska Airlines over a horizontal stabilizer repair. He said the plane was returned to service in proper condition.