The EU Court of Justice states that the Commission can require all necessary information including documents from a party involved in the proceeding without undermining the rights of defence (Orkem)

Case 374/87 Orkem v Commission of the European Communities* 1. A decision is properly notified if it reaches the addressee and the latter is in a position to take cognizance of it. Accordingly, a company notified of a decision requiring information to be provided pursuant to Article 11 (5) of Regulation No 17 cannot challenge the legality of the decision on the ground that the prior request for information provided for in Article 11(1) was addressed to its subsidiary if it had full knowledge of that request, as