It states: “Commissioners may not engage in any other professional activity, whether gainful or not.”
But papers from the Bahamas registry show she was registered as a director of Mint Holdings Limited between July 2000 and October 2009, according to documents reviewed by the International Consortium of Investigative Journalists.
The papers were released by Süddeutsche Zeitung, the same German newspaper behind the Panama Papers, and the International Consortium of Investigative Journalists.
When Ms Kroes joined the EU in 2004, she declared previous roles at an array of more than 60 companies including Volvo, McDonald’s, Thales and mobile phone group mm02.
However there was no mention of Mint Holdings.
In response to the claims, Ms Kroes said she did not declare her directorship of the company because it was never operational.