British Labour Party politician Peter Mandelson speaks to the media on college green outside the Houses of Parliament in central London. AFP
The European Commission made the request to the European Anti-Fraud Office (OLAF) "given the circumstances, and the significant amount of documents made available publicly", a spokesman for the executive said.
Brussels wants to determine whether the high-profile British politician breached the code of conduct to which both current and former commissioners are bound, including rules on secrecy and the ban on receiving gifts or favours.
Mandelson, 72, is at the centre of a political storm following the publication of troves of documents detailing his relationship with the convicted sex offender.
"As new documents were published recently, we are looking into these and assessing whether there is any breach of the respective obligations," the spokesman said.
The EU request, first reported by Financial Times, was sent on February 18.
Contacted by AFP, the EU agency would only say it had received the request.
Mandelson is also under investigation in Britain over allegations he sent sensitive documents to Epstein during his time as a government minister, including during the 2008 financial crash.
His links to the late financier, who died by suicide in a New York prison in 2019, have caused a furore in Britain.
Prime Minister Keir Starmer fired Mandelson as ambassador to Washington in September after a release of documents linked to Epstein showed the extent of their friendship.
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