Morrison & Foerster admitted it accidentally retained files from Anthony Levandowski, pictured, who formerly headed Uber's driverless car division. Photo: Eric Risberg/AP

SAN FRANCISCO — Morrison & Foerster revealed in a filing in federal court Wednesday that it accidentally kept copies of some documents from Anthony Levandowski, the star engineer accused of having stolen over 14,000 files from Google’s self-driving car division Waymo.

It is not clear whether any of the files that MoFo has in its possession are actually from Waymo, or whether they contain stolen trade secrets. MoFo said it does not know the contents of the “vast majority of these documents,” or whether they respond to a court order directing all files stolen from Waymo to be returned to the company.

The filing comes in response to demands made last week by U.S. District Judge William Alsup of the Northern District of California that MoFo answer why it should not be found in violation of his earlier order regarding Waymo’s files.

It’s the latest development in a fast-paced and complex saga arising out of Waymo’s trade secrets theft lawsuit against Uber Technologies Inc., which is being represented by MoFo and Boies Schiller Flexner. The suit alleges that Uber is using trade secrets stolen by Levandowski from Waymo, where he worked prior to founding a self-driving car startup called Ottomotto acquired by Uber.

Waymo’s attorneys at Quinn Emanuel Urquhart & Sullivan last month accused MoFo of withholding the fact that the law firm had access to some of the files downloaded by Levandowski in its dealings with Stroz Friedberg, a digital forensics firms that conducted due diligence for Uber prior to its acquisition of Ottomotto. But MoFo on Wednesday said it “ceased to have access” to those files before Waymo’s lawsuit against Uber was even filed.

However, the firm also said that in conducting a search for those materials, it stumbled upon the fact that it had retained copies of other files that Levandowski had given to Stroz Friedberg.

MoFo said it was given those files by Stroz Friedberg—with Levandowski’s authorization—because the law firm also previously represented Levandowski in two arbitration proceedings brought by Google. Those proceeding center on allegations that Levandowski poached Waymo employees to start Ottomotto in violation of his employment contract.

“In March 2017, we received some materials from Stroz (not all of them) and began review of these materials before Mr. Levandowski retained separate counsel. We stopped the review very shortly after we started because of the change in counsel,” wrote MoFo’s Eric Tate, co-chair of the firm’s global employment and labor group, in a declaration submitted to the court Wednesday.

At the same time, MoFo argued in the filing that it is not permitted at this time to hand over any portion of the files—regardless of what they contain—both because they are subject to attorney-client privilege and because Levandowski has since asserted his Fifth Amendment rights and refused to answer questions or turn over any files in connection with the Waymo lawsuit.

Alsup has ordered the due diligence report and related communications from Stroz Friedberg to be turned over to Waymo despite Levandowski’s privilege and Fifth Amendment claims. That order is pending appeal before the U.S. Court of Appeals for the Federal Circuit. (Appeals in the case go to the Federal Circuit because Waymo also alleged patent infringement claims.)

MoFo partner Arturo Gonzalez, one of Uber’s lead attorneys in the Waymo case, would not say whether the files MoFo received from Stroz Friedberg include documents that originated from Waymo. “We intend to comply with the Federal Circuit’s order on this important issue; until then, it would not be appropriate to comment on the contents of the documents,” he wrote in an email.

A spokesman for Waymo did not immediately respond to a request for comment.