FILE PHOTO: A Volkswagen logo is seen on a new car model at the 89th Geneva International Motor Show in Switzerland, March 5, 2019. REUTERS/Denis Balibouse

WASHINGTON (Reuters) - Volkswagen AG said the U.S. Securities and Exchange Commission may sue the German automaker over its failure to disclose its diesel emissions scandal to investors.

VW said in its annual report bit.ly/2HlE1Su released earlier this week that the SEC probe focuses on the automaker's nondisclosure of "certain Volkswagen diesel vehicles' noncompliance" with U.S. emissions rules.

Volkswagen did not have an immediate comment.

Volkswagen has agreed to pay more than $25 billion in the United States in connection with “Dieselgate” for claims from owners, environmental regulators, states and dealers, and has offered to buy back about 500,000 polluting U.S. vehicles.

VW admitted in September 2015 to secretly installing software in nearly 500,000 U.S. vehicles to cheat government exhaust emissions tests and pleaded guilty in 2017 to felony charges. In total, 13 people have been charged in the United States, including four Audi managers.

Regulators and investors have sought penalties and damages from Volkswagen, arguing the carmaker should have informed investors in a more timely fashion about the size and scope of fines related to its diesel emissions cheating scandal. German securities law requires Volkswagen to publish market sensitive news in a timely fashion.

Volkswagen admitted to U.S. regulators to having used an illegal “defeat device” on Sept. 3, 2015 but did not inform investors. The U.S. Environmental Protection Agency and California’s Air Resources Board made VW’s cheating public on Sept. 18, 2015.

Volkswagen has argued that it was not obliged to inform investors earlier because it did not believe it was facing fines in totaling billions of dollars.