EU investment bank 'furious' at being duped by Volkswagen

Hoyer was disappointed with the German car manufacturer because its emissions-cheating software had hidden the fact its diesel cars actually released up to 40 more times of nitrogen oxides in real-world driving than in tests.

He refrained from going into the details of the case, given the ongoing investigations in Germany and by the EU's anti-fraud office, Olaf.

The EIB granted the loan in 2009 in a wider effort to cut CO2 emissions from cars.

Volkswagen, along with other car manufacturers, had contacted the EIB to secure loans to help finance research and development of diesel technologies.

Asked how the EIB was duped and whether its due diligence was up to standard, a senior EIB official said they had learned from their mistakes.

"We were presented at the time, not just by Volkswagen, also by other car manufacturers with what we considered world-leading diesel technologies with the major aim of reducing CO2 emissions," said the official.

The official did not respond to a follow-up question on which lessons were learned.

EIB says they had obtained reassurances that the cars put on the road were compliant with emission regulations and would meet CO2 standards, noting that the vehicles had been "type-approved" by all EU states.

The scandal erupted in 2015 in the US. It was later revealed that the Volkswagen Group had equipped some 8.5m cars in Europe with illegal software.

Two years later, and Hoyer maintained the EIB loan had not been misused by Volkswagen.

But he changed his tune after it emerged the loan had indeed been acquired through "fraud" and "deception", according to media reports of the Olaf probe.

EUobserver had then asked Olaf to release the report but it referred press queries back to the EIB, while the EIB referred them back to Olaf.

The European Parliament also asked the EIB to release the report.

The EIB declined.