California is preparing a series of actions against automaker Volkswagen over its admitted cheating on tailpipe emissions tests, the state's top air official said on Thursday.
"Right now we are organizing ourselves for a major enforcement action," said Mary Nichols, chair of the California Air Resources Board.
She said it was too soon to say what penalties would be levied against the company, which admitted duping the tests last week.
The state is also preparing to oversee a recall of vehicles in California equipped with the device that allowed it to pass laboratory tests measuring their output of the air pollutant NOx, which contributes to smog, Nichols said.
Meanwhile, the number of investigations of the German automaker expanded again Thursday with confirmation that at least 27 U.S. state attorneys general have initiated a multi-state investigation of Volkswagen over its representations to consumers over their diesel vehicles.
As part of the probe, the group will send subpoenas to Volkswagen, said a spokeswoman for Illinois Attorney General Lisa Madigan.
News of the subpoena and state attorneys general participating in the group so far comes two days after New York Attorney General Eric Schneiderman said a group was forming to probe the carmaker over the U.S. emissions test scandal.
The automaker also faces a criminal probe by the U.S. Justice Department and numerous overseas investigations.