Uber says that a detour in its software development “could limit or delay our production of autonomous vehicle technologies.”

The company's statement appeared in a quarterly securities filing on Tuesday, and it is most probably related to a trade secrets dispute with Alphabet's Waymo.

Uber declined to provide any additional information.

An expert review of Uber’s software unveiled that the company was still used technology from the Alphabet's unit. The review was part of a legal settlement reached in February 2018 that brought to an abrupt halt a federal jury trial over whether Uber unfairly benefited from confidential ideas allegedly secured by making former Waymo engineers key members of its self-driving car team.

Last April, Uber disclosed that the expert software reviewer’s interim findings were mixed and could be costly.

The ride-hailing giant has been trying to catch up to Waymo in the development of software and hardware to install in cars and trucks to allow for driverless taxi and delivery services.

Waymo began its autonomous car project within sister company Google a decade ago, while Uber launched its effort four years ago.

Waymo said that the independent software expert’s findings “further confirm Waymo’s allegations that Uber misappropriated our software intellectual property. We will continue to take the necessary steps to ensure our confidential information is not being used by Uber.”

It is unclear whether Uber will be forced to strike a licensing deal with Waymo or opt for costly changes to its autonomous driving software.

The United States National Transportation Safety Board in a recent report there were software flaws in an Uber self-driving test vehicle that struck and killed an Arizona woman in the middle of a road last year.

The Uber unit drew a $1 billion investment in April from SoftBank Group Corp, Toyota Motor Corp and automotive company Denso Corp.