Germany is subjecting diesel vehicles including those from foreign manufacturers to strict checks, its transport minister said, following Volkswagen's latest disclosure that it gave false data on CO2 emissions.

In a deepening scandal, Volkswagen on Tuesday said it had understated the fuel consumption and carbon dioxide emissions of about 800,000 vehicles sold in Europe.

VW in September admitted that it had cheated on diesel emissions tests in the United States.

"We are currently carrying out strict checks on diesel vehicles from other manufacturers including foreign ones," Transport Minister Alexander Dobrindt told the Bild daily in an interview published on Saturday.

Dobrindt said the European Union was working on tougher car emissions tests for the future, which would include tests on the road as well as in the lab.

"The tests will therefore become more strict and will more closely resemble the normal driving behaviour in road traffic," he told the newspaper.