German investigators are looking into whether Volkswagen executives or engineers broke laws by lying about carbon dioxide emissions in 800,000 cars sold in Europe, the New York Times reported.

Authorities near the automaker’s headquarters in Wolfsburg say they are focused on five Volkswagen employees, but wouldn’t identify those employees. Investigators are determining if Volkswagen employees knowingly provided false information to authorities about those cars and their emissions to qualify those cars for lower tax rates. In admitting that it lied about its emissions levels this month, Volkswagen said it would repay governments for back tax revenue lost because of the bogus claims.

This month, Volkswagen admitted it underestimated carbon dioxide output from 800,000 cars sold in Europe and said the scandal could cost the company more than $2.1 billion. According to the New York Times report, Volkswagen’s admission included a promise to repay taxes owed on owners’ cars it sold with bogus carbon dioxide numbers.

Volkswagen could face similar levies by European governments for its broader, deeper scandal with their diesel-powered cars. Millions of those cars in Europe will need costlier fixes, and emissions levels for those cars could have exceeded by several times the legal limit.

Volkswagen set aside more than $7 billion to pay for its diesel scandal, but that’s likely to be a fraction of the overall cost to the automaker.

On Monday, Volkswagen announced the German transportation authority approved initial fixes for about 70 percent of the cars on the road there. The fixes for its 1.2- and 1.6-liter engines (not sold in the U.S.) and some 2-liter diesel engines would likely be software updates and bigger air filters that would cost about $10.

Last week, Volkswagen submitted its plan to U.S. regulators to fix their illegally polluting cars. According to the California Air Resources Board, officials have up to 20 days to review the proposed fix.