Former EU's antitrust chief Neelie Kroes | Anthony Harvey/Getty Images for TechCrunch Commission wants Neelie Kroes to explain Bahamas deal Jean-Claude Juncker has written former EU antitrust chief about failure to disclose business position.

The European Commission demanded that Neelie Kroes explain her failure to disclose that she was director of an offshore company in the Bahamas during her time as the EU's antitrust chief, in clear violation of ethics rules.

The Commission's chief spokesman, Margaritis Schinas, faced a barrage of questions Thursday about the news that Kroes had held the position during her time as a member of the EU executive body. The information was revealed Wednesday in leaked documents published by the International Consortium of Investigative Journalists.

Jean-Claude Juncker, the Commission president, sent a letter to Kroes seeking further details about the disclosure violation, Schinas said. Based on her response, EU officials said, the Commission would decide whether to pursue disciplinary action or if additional steps were needed, such as scrutinizing her current business dealings.

The Commission and Juncker have been embroiled in a controversy in recent days over potential conflict of interest issues raised by the former Commission President José Manuel Barroso, who in July accepted a senior executive position with Goldman Sachs.

One potential sanction in such cases is to revoke a former commissioner's EU pension. But Schinas said 75-year-old Kroes is not receiving a pension — revealing a potential gap in the Commission's ethics and accountability procedures.

Kroes, who now holds paid advisory positions with Uber and Bank of America, was the top Commission official in charge of competition and later its digital agenda policies between 2004 and 2014. She was listed as director of the Bahamian company Mint Holdings Limited during at least some of that period, according to the leaks.

EU officials said Kroes or her lawyer had sent an email to Juncker late last week informing him of the failure to disclose her directorship with Mint Holdings. The Commission, however, failed to see the email for days and did not respond until Thursday after repeated press inquiries, officials said.