Volkswagen's cost for ending civil lawsuits over its emissions-cheating scandal has grown to $15 billion, Bloomberg News reported Monday on the eve of the automaker's court deadline to file a settlement.

Last week, a person close to the matter told AFP that the German automaker would file a proposed settlement of $10.3 billion. That included compensation payments to owners of the some 480,000 2.0 liter diesel cars secretly outfitted with illegal emissions-spoofing devices as well as funding for a program to fight air pollution.

The proposed settlement that Volkswagen must file Tuesday in a San Francisco federal court will include $5 billion more than the $10 billion it had previously reported, Bloomberg reported, citing two sources familiar with the negotiations.

Volkswagen will pay $2.7 billion in fines to the US Environmental Protection Agency (EPA) and the California Air Resources Board, and spend $2 billion on clean-emissions technology, one of the people told Bloomberg.

The automaker is expected to announce a settlement with states, including New York, for roughly $400 million, another person said.

Volkswagen admitted in September that it had installed software in diesel cars that tricked US emissions tests into showing the cars met environmental standards.

The device switched off after testing, enabling the vehicles to spew up to 40 times the permitted amounts of nitrogen oxides.

The San Francisco civil lawsuit accuses Volkswagen of major damages to the environment and the owners of the illegally rigged cars.

The agreements between VW and the US Justice Department, EPA and California Air Resources Board are to be filed by noon (1600 GMT) with Judge Charles Breyer of the US District Court for the Northern District of California.

Contacted by AFP, the Justice Department declined to comment on the report.

Volkswagen has set aside 16.2 billion euros ($17.9 billion) to cover costs from the scandal, including seven billion euros for legal risks.

A settlement would not end Volkswagen's troubles in the United States, however.

The company must address similar charges over its 3.0 liter diesel cars with emissions-cheating devices.

VW also faces fines from US regulators potentially running to the tens of billions of dollars, and a criminal investigation over the scandal.

It is facing similar charges and litigation in Europe and elsewhere for the same issues.