BRUSSELS — European Union officials, questioned about new revelations of corruption and exploitation of the bloc’s farm subsidies, said Monday that outright fraud was very rare and that auditors swiftly rooted it out.

But they also acknowledged that law enforcement often fell to the same national leaders who warp the system — and benefit from it.

“We are not here to replace national governments,” said Mina Andreeva, a spokeswoman for the European Commission, the administrative arm of the 28-nation European Union.

The responses at a daily news briefing came after a lengthy New York Times investigation that showed how oligarchs, populist leaders and their families had made millions of dollars from European farm subsidies, often based on dubious land deals or outright corruption.